Apple Orchard v2n1 1981 Spring

===> presents | A Dp E hard Orc SPRING 1984 The IAC is coming to Chicago in May! Chicago Convention anc \d Tourism Bureau soecials VISICALC 124.95 PANASONIC COLOR MONITOR 395.00 DESKTOP PLAN 165.00 CENTRONICS 737 795.00 APPLE TAX PLANNER 95.00 INTERFACE CABLE for 737 25.95 APPLE FORTRAN 159.95 MICROSOFT "RAMCARD" 167.50 MONTY PLAYS MONOPOLY [disk] NEC GREEN PHOSPHOR MONITOR 229.95 VERSAWRITER — Graphi 219.95 jeu) pa AMERICA’S INFORMATION UTILITY XYM EX + 1000 with Quadra-Pitch 10, 12,15 Pitch and Proportional Spacing D.C. Hayes Micromodem II™ CORVUS 10 MEGABYTE HARD DISK BASF DISKS NOW! Corvus speaks Apple pascal! $25.95 for 10 APPLE DISK DRIVE Reg. $525 now $459.95 LANGUAGE SYSTEM $425.95 APPLE /// 128k price $4350.00 $3995.00 WORD PROCESSING COMBO! OUNE: PRINTER 5/45 $2495.00 EasyWriter with a Videx Board only $450.00 Westwood Computer a ‘computer Sales and Service Systems (213) 475-5467 Telephone Orders Only : software Whoneedsit? For small amounts of information a pencil and paper filing system works great. But when you want to keep track of hundreds of pieces of information this system has limitations. Recording information is slow, locating what you want can be impossible, and the system is so time consuming it keeps you from filing information you know is valuable. With PFS software and an APPLE* , computer you have a powerful alternative. : Using the concept of designing a form on [ the screen, PFS lets you create a file of information on any subject you wish without programming. You can catalog your stereo record collection, 35mm slides, magazine articles, daily ex- penses, or your club’ membership list. Using PFS at work you can make better decisions by creating files on inventory, customers, or or ders and accessing them in seconds. To use PFS you simply design a form on the screen by typing the names of the items you want to store in- formation about. Once the form is created you tab from PFS isa trademark of Software Publishing Corporation. requiresa 48K, 16-sector disc based APPLE Il system item to item and fill in the information. This can be a single piece of data or several pages of text. Up to 1000 forms can be stored on a diskette. Looking up information is just as easy. PFS can search for a number, a single data item, or a word within a page of text. All forms that match are displayed on the screen. You can browse through each one and change, delete, ex- \ pand, or print it. PFS even has a print for matter that lets you create mailing labels. PFS software is different. It is not a specialized application package or a complex programmer oriented data base manager. It is a personal filing sys- tem that lets you communicate with the computer using meaningful every- day concepts to rapidly create files on any subject matter you require. PFS isavailable through your local dealers. Ifthey don’t carry it, have them give us a call at (415) 368- 7598 or write to us at Software Publishing Corp- e,] oration, RQ Box 50575, Palo Alto, CA 94303. “APPLE isa registered trademark of Apple Computer Inc. Software Publishing Corporation .4 MEGABYTES FOR YOUR APPLE Double-Sided, Double-Density 8-Inch Drive Capability is Here ... Now! The new LOBO DRIVES Model LCA-22 Double Density Floppy Disk Controller has been specifically designed to match your APPLE® to the new double-sided, double-density 8-inch floppy disk drives. Now, you can add up to four 1.1 Megabyte drives (4.4 Megabytes total) and realize all the power and potential of your APPLE computer. Completely Software transparent, the Model LCA-22 will plug into any chassis slot. You are no longer restricted to slot 7. And, the Model LCA-22 is fully compatible with 3.2. (3.3 DOS systems, PASCAL will be available soon.) LOBO’s new LCA-22 Disk Controller and full line of field-proven, high-reliability disk drives (all LOBO products come with a one year, 100% parts/labor warranty) are available at computer retail stores nationwide. Stop in and see a demonstration at your local dealer today. LOBO DRIVES INT’L 354 South Fairview Ave. Goleta, CA 93117 (805) 683-1576 \@B Orives INTERNATIONAL (area code) Gaesces tear ee a ee 1 ' ' + I’m looking to expand my APPLE. Please ; t send me more information on: t ' 1 {© Model LCA-22 Disk CO Fixed Disk Drives : ! Controller ' ! Gi Floppy Disk Drives 1 5%-inch H ! 0 5%-inch C1 B.inch H + © 8inch 14-inch ‘ H t {Name t ' t 1 Address ' \ City State Zip t n | Phone i 1 1 1 t L 4 SPRING 1981 PRESIDEN APPLE ORCHARD In the past months the IAC has been receiving many phone calls and letters and the main question asked is “What can the IAC do for my club?” As a member club, you receive APNOTES which Apple Computer, other manufacturers and members give the IAC for distribution. They contain information on hardware/ software modifications/fixs and any other data that can help the end user with his/her Apple. As of this time, the IAC has sent over 140 pages of APNOTES. As a member club, you also re- ceive software disks that have been donated by clubs as far away as Japan and Australia, and as close as Apple Computer itself. So far there have been five official disks re- leased by the IAC to its members, and we hope to have one a month starting in May. If you are a new PAGE 3. member club, the IAC does not end back issues of the software, ut commences sending the cur- rent disk at the time of joining. The software is given FREE to our mem- ber clubs. The IAC publishes the “Apple Or- chard”, which is made available at a bulk discount rate to our member clubs. You can also individually subscribe. An additional monthly bulletin is also sent to our member clubs to inform them of late news and developments. The IAC has committees dealing with all manner of special interests. You can communicate with these committees by writing and making use of their experts. In the near future we hope to establish a WATS [800] line to answer some of your questions. There is in the planning stage a “scholarship” fund, and we will be video taping the seminars given at our annual meeting so we can send them to you for viewing. As the di- rectors from each region receive your inputs we, the IAC, will act on them. Now back to the question “What can the IAC do for my club?” | would like to change that to read “What can you as a member club contribute to help the IAC?” We need programs to distribute to the members, we need articles for the Orchard, we need your input. The IAC is a volunteer organization and without INPUT there is no OUTPUT. Ken Silverman, President, International Apple Core INTERNATIONAL APPLE CORE SPONSORING MEMBERS I.A.C. sponsors are a special breed. They are the organizations who along with our advertisers, contri- bute to and support many I.A.C. activities. In addition, they will provide us with application notes con- cerning their products—notes that will benefit users by showing new and different ways to utilize their products or production/software modifications that have been made to upgrade their product. When considering a software or product purchase, we request that they be given special consideration. Those organizations that would like to become sponsors or who would like additional information about the benefits and advantages of becoming a sponsoring member are urged to contact Michael Weinstock, Vice-President, International Apple Core, P.O. Box 976, Daly City, CA 94017. A list of sponsoring members, current through the first of February, 1981, appears on page 68. (continued on page 68) PAGE 4 APPLE ORCHARD INTERNATIONAL APPLE CORE™ PRESENTS Vol. 2 No.1 Spring 1981 Entire Contents Copyright® 1981 by International Apple Core Published for the International Apple Core by dilithium Press, P.O. Box 1493, Beaverton, OR 97075 SPRING 1981 President's Comer IAC Sponsoring Members Select One PRINT FRE(ed) Screen Formatting of Text ‘An Introduction to Light Pens IN THIS ISSUE Notes on Hi-Res Graphics Routines in Applesoft ‘An Apple ll Quickie Practical Super Hires Graphics ‘Comparing Applesoft Programs for Differences Charles Boody, David W. Walker, Val |. Golding 22 2 Sided Disks 5. H. Lam Routine Utility Double-Size Graphics for the Silentype Matix Functions with the Apple Programming the Apple to Communicate by Telephone Resurrecting Killed Programs Lookit ‘ANote on CPIM Programmer's Aid RAM Test Initializer Text Train and Sub Search Word of Caution Getting There Faster in Applesoft Basic Modifying Pascal BIOS to Work with the Paymar LC Adapter Craig Vaughan, Lee Meador 47 Simple Functions in Applesoft Homebrew to Champagne ‘The Apple Il Cassette Interface ***SYNTAX ERR New Product Parade Application for Membership Sorting in BASIC IAC Membership Information IAC Miscellany Who was Asking About ASCII? Passing Argument Values to Machine Language Subroutines in Applesoft Low Resolution Graphics in Pascal Color Compliments for Black and White Green Apple Bits Tune Your Apple Proper Printer Protocol Single Drive Copy ‘Advertisers Index Ken Silverman 3 3 TheEditor 6 Val.J.Golding 7 Peter C. Weiglin Neil D.Lipson 14 C.K. Mesztenyi 17 Gordon Stallings 19 R.H.Good 20 Lee Reynolds 28 Bruce F.Field 30 Max|.Nareff 36 Terry Guerrant 40 DavidG. McDonald 41 Steve Jenkins 43 GaryM.Comeau 44 David B.Garson 45 D.laden 45 David Bartley 46 D.B.Buchler 47 Steve Wozniak 51 Mark Crosby 61 ArtMack — 68 Joe Budge 73 Val.J.Golding 74 C.K. Mesztenyi 77 BillShepard 80 Tom Jacobsen 86 Mark Welty 86 Valj.Golding 91 Steve Adams 92 Jill A. Scofield — Publisher Val J. Golding— Editor Kathryn Hallgrimson—Assistant to the Editor Tymera Coen—Production Manager Larry Danielson—Circulation ADVERTISING REPRESENTATIVES. dilithium Press P.O. Box 1493 Beaverton, OR 97075 (503) 646-2713 SUBSCRIPTIONS — DEALER INFORMATION Apple Orchard Subscriptions P.O. Box 1493 Beaverton, OR 97075 $10/year— Published Quarterly For information on becoming a member of IAC please write: International Apple Core P.O. Box 976 Daly City, CA 94017 INTERNATIONAL APPLE CORE Jerry Vitt Ken Silverman Michael Weinstock Dave Gordon Joe Budge Jon R. Lawrence Harlan G. Felt Jerry Vitt Scott Knaster Bernie Urban Tony Cerreta Joe Alinsky Fred Wilkinson Roger Keating ‘Auby Mandell Wolfgang Dederichs Apnotes Apple Fair Apple Orchard Constitution & Bylaws Education SIG Ham Radio SIG Handicapped SIG 1.A.C. Software Legal SIG Medical SIG Newsletter Exchange Newsletter Library New Club Assistance Standards Telecommunications Officers Chairman President Vice-President Treasurer Secretary Regional Directors (north) (north) (south) (south) (east) (east) (west) (west) International Directors (214) 369-7660 (415) 878-9171 (516) 360-0988 (213) 954-0240 (919) 489-4284 (313) 534-2433 (408) 866-1733 (214) 369-7660 (303) 355-2379 (301) 229-3458 (914) 636-3417 (213) 703-1894 (415) 585-2240 P.O. Box 448, Double Bay 2028, NSW, Australia 409 Queen St. W., Toronto, Ont. Canada M5V 2A5, ‘Auf Drenhausen 2 4320 Hattigen, West Germany Committee Chairmen John Shanes David Alpert Val J. Golding Ken Silverman Ted Perry James E. Hassler, WB7TRQ David McFarling Neil Lipson Butch Clayton Dr. Larry L Stoneburner David Alpert Major Terry N. Taylor Randy Fields Mark Robbins Craig Vaughn (804) 746-2711 (312) 295-6078 (206) 932-6588 (415) 878-9171 (916) 961-7776 (307) 632-4934 (420) 467-1878 (215) 356-6183 (803) 884-5370 (714) 953-9151 (312) 295-6078 (213) 372-4134 (415) 775-7965 (303) 750-5813 (703) 255-2241 Ural MTTETETY? | Turn your Apple into the world’s most versatile personal computer. The SoftCard™ Solution. SoftCard turns your Apple into two computers. AZ-80 and a 6502. By adding a Z-80 microprocessor and CP/M to your Apple, SoftCard turns your Apple into a CP/M based machine. That means you can access the single largest body of microcomputer software in exist- ence. Two computers in one. And, the advantages of both. Plug and go. The SoftCard system starts with a Z-80 based circuit card Just plug it into any slot (except O) of your Apple. No modifications required. SoftCard supports most of your Apple peripherals, and, in 6502-mode, your Apple is still your Apple. CP/M for your Apple. You get CP/M on disk with the SoftCard package. It's a powerful and simple-to-use operating system. It supports more software than any other microcomputer operat- ing system. And that's the key to the versatility of the SoftCard/Apple. CIRCLE READER SERVICE NUMBER BASIC included. A powerful tool, BASIC-80 is included in the SoftCard package. Running under CP/M, ANSI Standard BASIC-80 is the most powerful microcomputer BASIC available. It includes extensive disk I/O statements, error trapping, integer variables, 16-digit precision, exten- sive EDIT commands and string func- tions, high and low-res Apple graphics, PRINT USING, CHAIN and COM- MON, plus many additional com- mands. And, it’s a BASIC you can compile with Microsoft's BASIC Compiler. More languages. With SoftCard and CP/M, you can add Microsoft's ANSI Standard COBOL, and FORTRAN, or Basic Compiler and Assembly Lan- guage Development System. All, more powerful tools for your Apple. Seeing is believing. See the SoftCard in operation at your Microsoft or Apple dealer. We think you'll agree that the SoftCard turns your Apple into the world’s most versatile personal computer. Complete information? It's at your dealer's now. Or, we'll send it to you and include a dealer list. Write us. Call us. Or, circle the reader service card number below. SoftCard is a trademark of Microsoft. Apple I! and Apple I! Plus are registered trademarks of Appie Computer. Z-80 is a registered trademark of Zilog, Inc. CP/M is a registered trademark of Digital Research, Inc. Microsoft Consumer Products, 400 108th Ave. N.E., Bellevue, WA 98004. (206) 454-1315, PAGE 6 APPLE ORCHARD. FROM THE EDITOR’S NOTEBOOK SCRATCHPAD RAVINGS ASSISTANT ASYLUM SELECT ONE SPRING 1981 It seems incredible that an entire year has rolled past since we put the first Orchard to bed and cele- brated the new arrival, but it has and we are. Celebrating the arrival of the fourth Orchard, 96 pages of fact and information filled articles and programs. Leading off this anniversary issue on Page 9 is Peter C. Weiglin’s Screen Formatting of Text, a well written article from the San Fran- cisco Apple Core’s Cider Press, and of special significance to new- comers to Appledom who want to learn more about the Apple's easy to use screen display commands. Our second major contribution is by C. K. Mesztenyi of the Washing- ton, D.C. Apple Pi group, who has greatly expanded on the Applesoft Hi-Res Internals information from the first Orchard, with his Notes on Hi-Res Graphics Routines in Apple- soft. This feature makes it truly pos- sible for the first time to utilize the speed of Applesoft’s Hi-Res routines from Assembly Language. One of Call -A.P.P.L.E.’s bestowals is a substantial rewrite by David W. Walker and ourselves of Charles Boody’s Comparing Applesoft Pro- By the Editor grams for differences, a program that is helpful to the utmost when you can’t remember exactly what changes you have made to the pro- gram you are working on. Call -A.P.P.L.E. and Cider Press each appear on the scene again with Lee Reynolds’ 5. H. Lam Rou- tine Utility, a handy program that converts machine language to BASIC, and Max Nareff’s thorough exploration of Matrix Functions with the Apple. Have you ever wondered what ASCII really means? Our explana- tory article offers some clues as to how the ASCII standard character set and Apple display set differ, while Washington Apple Pi also puts in another appearance with Bruce Field’s Double Size Graphics for the Silentype and C. K. Mesz- tenyi’s really neat method of pass- ing parameters to the A, X, Y and PC registers from BASIC. Pascal users should not feel ne- glected either, with a passel of goodies, including Low Resolution Graphics in Pascal by Bill Shepard, nor is CP/M overlooded, as Steve Jenkins contributes A Note on CP/M. In Apple Computer, Inc.'s Con- tact, co-founder Stever Wozniak describes some of the events pre- ceeding Apple | and the Apple JL, under the title Homebrew to Cham- pagne. “Woz” was recently injured while taking off in his aircraft, but is doing very well. We are certain any cards would be well received, and may be sent c/o Apple Computer, Inc., 10260 Bandley Driver, Cuper- tino, CA 95014. Finally, in the International Apple Core section, you will find the first of several new features, Mark Cros- by’s New Products Parade, along with information as to how you, as an individual, can subscribe to the Orchard, or locate a user group near you to join. User groups, in turn, will find how they may join the I.A.C. Don't forget, we are just scratch- ing the surface. It would take another two or three pages just to describe all the fine material under these covers; best you look for yourself. To make sure you don't miss out on our next big batch of brilliant booleanisms, better buy a subscription. (whew!) SPRING 1981 APPLE ORCHARD PAGE7 EDITOR RESIGNS, CLUB IN UPROAR PRINT FRE(ed) By Val J. Golding Got your attention, there, didn’t I! So commenced a story by Lee Meador in the Ft. Worth Apple User's Group Newsletter, and griping about much the same situa- tion as we are about to espouse. Contributions. It is not the almighty dollar we are talking about, but the almighty arti- cle. This issue of the Apple Orchard would not have at all been possible without the efforts of three of the largest user groups in the country: San Francisco Apple Core (Cider Press), Washington, D.C. Apple Pi (Washington Apple Pi) and Apple Pugetsound Program Library Ex- change (Call -A.P.P.L.E.). To these three organizations, then, we must first extend our thanks and our con- gratulations for coming through ina pinch. It seems inconceivable that the member clubs of the International Apple Core, now numbering well over 200, with just minor excep- tions, submitted not so much as one original or reprint story for this issue of the Orchard. We have read many, but not enough, issues of the club newsletters to know that there is a wealth of material out there that would be of much interest to many of the readers of the Orchard. If the president of each club, or the editor of its newsletter, would take just a few moments to review material they have recently pub- lished and recommend it to us, we would have enough material for the next year or two of the Apple Orchard. The IAC is an organization that provides a multitude of services to its member clubs, not the least of which is free public domain soft- ware. In return, each member club has a responsibility, an obligation, to reciprocate in the form of mater- ial for the Orchard. The Orchard was, and remains, the primary source of financial support for the IAC. Without its revenues, the IAC could not survive. This editorial is no idle threat; it is a statement of fact. We will bandy no words. Your support is needed, and it is needed now. IN MEMORIAM: Apple Orchard Vol. Il, No. 2 Summer, 1981 After you play the Temple of Apshdi, you can play Sticks and Stones for free. Within the 200 rooms and catacombs of the Temple of Apshai, untold treasures await you — the hero. All you have fo do is elude, outsmart and outwit the beasts, monsters and demons lurking in the dark labyrinth. Spend minutes or hours on this role-playing fantasy — the boldest computer game in our Dunjonquest™ series. Now, when you order the “Temple of Apshai,’ you get the “Sticks & Stones” board game for no extra charge. In fact, if you're not satisfied with the “Temple of Apshai,’ you can return it within 10 days and still keep “Sticks & Stones!” But don’t wait, this special offer is limited. (We'll also send you a catalog outlining our other exciting com- puter games). (Add $1.00 shipping and handling charge; plus 6% or 672% tax for California residents.) 1 | I Automated Simulations, P.O. Box 4247, 1988 Leghorn Street Name. | | Mountain View, California 94040 Department AO I | Please send me the “Tempe of Apshat or: nares | | Cassette ($24.95) Disk ($29.95) 7 I | _TRs-80 TI 16K, Level it 32K TRSDOS ; ! | _ APPLE Not available Cl 48K Applesoft in ROM Clty, State, Zip i | PET 032k Not available 1 Check enclosed, Charge to: 1 VISA C) MasterCard | | | | | | | | | i Amount $. # Expiration date. r charge by phone: (800) 824-7888, operator 861. In California: (800) 852-7777, ‘operator 861. Ityou prefer, call these numbers fr a lst ofthe computer stores near you Verbatim comments: ®€Compared to the brands I've used before, Verbatim Datalifé'is the best yet! 99 Sandy Tiedeman Las Vegas, NV &€New Verbatim helped eliminate I/O errors on my Apple.99 Richard Adams Ft. Walton Beach, FL I would prefer Verbatim Datalife over any brand I've ever used.99 Skip Piltz Overland Park, KS &¢My experience with Verbatim diskettes has been excellent. I've used several boxes over the past few months and they've all been error-free.99 Robert Roeder Las Vegas, NV e¢Much stronger, better centering. A definite im- provement.99 Leroy LaBalle Marrero, LA eet has worked perfectly everytime!99 Richard Ruth Shippensburg, PA €t] like the thicker pro- tective cover.99 David Hendel Lititz, PA Great! I have had no problems!99 Timothy Roscoe Mechanicsburg, PA &€So far my Verbatim disks have been performing flaw- lessly. Not always so with other disks.99 Chris Otis Hoffman Estates, IL €¢Runs quieter in the disk drive.99 Richard Cannova Los Angeles, CA €Verbatim disks are super. They're our standard for quality.99 Bob Mills Mission, KS €tAnything that prolongs the life of a diskette is a plus. Thank you Verbatim for an excellent improvement.99 Steve Toth Piscataway, NJ Of the 130-plus Verbatim disks I have, I'm not aware of any problems. I'm sure the improvements will give your disks an even longer life.99 Gerald Janas Warren, MI ReFANTASTIC. Nota single registration problem. Much more reliable than what I had been using.99 Gary Sandler Playa Del Rey, CA €¢Verbatim is much more reliable. I wouldn‘t trust anything else.99 Howard Chin Pomona, CA €¢Thank you for the im- provements. Just another reason why I'll always use Verbatim.99 James Hassler Cheyenne, WY We introduced Verbatim Datalife mere months ago. And it’s already playing to rave reviews like these. But don't take anybody else's word for it. Try it your- self, and see if you don't agree it's the best media you've ever tried. For the name of your nearest Verbatim dealer, call (800) 538-1793, in California call (408) 737-7771 collect. We play it back, Verbatim! SPRING 1981 APPLE ORCHARD. PAGE9 SCREEN FORMATTING OF TEXT One of the more satisfying sights in Apple land is watching as your program successfully runs and information is being displayed on the CRT (Cathode Ray Tube, or TV screen to most of us). Lists of infor- mation scroll by—bunched up against the left margin, maybe, and with numbers not quite lined up, but printing, by golly. But soon, the desire to make things look a bit neater wells up inside of us, par- ticularly if we're going to show this thing off to anyone else, like for ex- ample with a project involving our work. So let's take time here to consider the formatting of data. At the outset, | must say that this material has been gathered from many sources. Further, there must be better ways to do some of these things, or at least alternate methods which you may have. If so, please let us know about them. The BASIC commands which play a part in formatting include: PRINT TAB HTAB SPC() FLASH INVERSE NORMAL VTAB INPUT GET SPEED STR$( LEN( VAL( ASC( CHR$( HOME (or CALL -936) CALL -958 CALL -868 POKE by Peter C. Weiglin Cider Press ©1981, All Rights Reserved —and others. The primary statement is, of course, PRINT. All else is format- ting which characters we place on the screen, and where we place them. Within the limitations of the 40-character wide screen and the Apple character set, there is vir- tually nothing that can’t be done. (There is both hardware and soft- ware available which bends these limitations, but let’s stay with the unadorned Apple for now.) The PRINT statement causes dis- play of letters, numbers and all sym- bols except the double quotes (”). The reason you can’t display double quotes is that this symbol is used to tell the Apple where material to be printed starts and ends. No prob- lem; we have single quotes (’) avail- able to pinch hit. Example: 10 PRINT “‘HELLO’, SHE SAID AS WE” Whatever you put between dou- ble quotes will be PRINTed. Some things can be PRINTed without quotes, namely numbers and pre- viously identified strings. Examples: PRINT 250 PRINT 4+6 30 X=5 40 PRINT X 50 X$= “CIDER PRESS” 60 PRINT X$ In addition, Applesoft will allow the double quote within a PRINT statement, through the use of CHR$(34). To rewrite our example above: 10 PRINT CHR$(34); “HELLO”; CHRSG4); “, SHE SAID A‘ What about this one? 70 PRINT Well, the PRINT command by it- self brings about a line feed and [RE- TURN]; it's the equivalent of skip- ping a line. How about this? In Applesoft, a quick way to type [PRINT] is to type a question mark as a shorthand symbol. 80 ? “APPLE CORE” will yield 80 PRINT “APPLE CORE” when the line is LISTed. This not only saves typing strokes, but also allows you to edit a program line more quickly, by taking advantage of the four-character difference be- tween [?] and [PRINT]. All of these PRINT commands so far will begin their display at the left side of the screen. Here's the first approach to making the right-hand phosphors carry their share of the load: 90 PRINT “ APPLE” PAGE 10 Sure; put in enough spaces to get you as far to the right as you want to be. Oh...if you put in more than 40 spaces, you'll continue the word on the next screen line. Well, there are easier ways to break free of the left margin; [TAB] in Integer Basic and [HTAB] in Applesoft Basic. They work the same way in their respective dia- lects; let’s use the Applesoft version: 100 HTAB 8 110 PRINT “APPLE CORE” ~and the first letter of the print statement will appear 8 spaces from the left margin. We risk duplicating the Apple manual here because there has been some confusion about [TAB], since it appears also in Applesoft, but as a slightly different function, and there is no “Integer/ Applesoft comparative manual". SIDE NOTE: THERE IS ONLY ONE “R” IN THE WORD “INTEGER!” Regarding [TAB] and [HTAB], the lowest legal value you can use is 1; the highest is 255. (Well, you could use [HTAB 0], but only if you wanted to tab 256 spaces.) Note too, that the [HTAB] com- mand can cause the next item to be printed to the left or right of the cur- rent cursor position. Try this: 120 HTAB 20:PRINT “E”;:HTAB 10:PRINT “A” Yep, the “E” was printed first, then the “A” to the left of the “E”, on the same line. Now try it without the semicolon after the “E”, and you see that the “A” is one line lower. But before we get into the semi- colon and other delights, let's clear up the Applesoft [TAB] first. Note that in Line 100 above, [HTAB] stood by itself as a command. So does [TAB] in Integer. [TAB] in Ap- plesoft does not; it must be in- cluded in a [PRINT] statement, with the number in parentheses, like this: 130 PRINT TAB(8) “APPLE CORE” APPLE ORCHARD Why do we bother with [TAB] in Applesoft at all? Frankly, | dunno. [HTAB] runs a bit faster than [TAB] and [TAB] cannot move the cursor to the left. Anybody have the answer? Now try this: 140 A=7 150 HTAB A: PRINT “APPLE” Yes, you can [HTAB] to a variable, too, which leads to all kinds of pos- sibilities. You may have noticed one application of this in an S. F. Apple Core Disk of the Month: 160 C$= “APPLE CORE” 170 HTAB (20- INT(LEN(C$)/2)) 180 PRINT C$ Since 20 is halfway across the screen, and we're HTABbing 20 minus one-half the length of the string, the string will automatically be centered. If you want to print C$ so that it will be flush with the right- hand margin, make line 170 above read this way: 170 HTAB (41- LEN(C$)) Yes, that’s “41”, not “40”. The last character of the string will occupy the 40th space on the screen, which is the rightmost space. We also lightly scratched the sur- face of ways to print more than one item on the same line. This is most often done with semicolons, al- though commas and the [SPC( )] command are also available. Try this: 190 PRINT “APPLE”; ”;“CORE” —and you get the space between the two words. The semicolons tie the elements of a PRINT statement together. Remember, a PRINT state- ment normally contains an auto- matic RETURN within it; the semi- colon inhibits that RETURN. For example: 200 PRINT “APPLE”; 210 PRINT“ ”; 220 PRINT “CORE” SPRING 1981 —and all is on the same line, even though three program lines were used. The comma in a PRINT statement also inhibits the carriage return -or line feed, but it does so in a very specialized way. The line 230 PRINT “A”,“B",“C“,“D” —causes the “A” to be printed at the left margin, the “B” in the 17th space, the “C” in the 33rd space, and the “D” in the first space on the next line. These locations are fixed; while you use the comma, you can't change them. It'll go 1, 17, 33 ‘till Kingdom come. To print columns, you can use the comma, or you can use a formula which gives you better control of the columns. Let’s assume a list of 30 items, each 6 characters wide. If you just [PRINT] that list, it'll scroll the first items on the list right off the screen. But if you split it into two columns, it'll all fit. Try this: 240 FOR I= 1. TO 15 242 PRINT S$(I); 244 HTAB 20: PINT S$(I+ 15) 246 NEXT For more than two columns, the general idea is the same; divide the total number of items in the list by the number of columns you want, and add 1. That becomes the top number in the for-next loop. As an example, for three columns, with 48 items, it’s: 250 RN=48 251 N=(RN/3)+1 252 FOR I=1 to N 253 PRINT S$(I);:HTAB 15 254 PRINT S$(N + 1);:HTAB 30 255 PRINT S$(2*N) +1) 256 NEXT I —Note the semicolons used in lines 253 and 254 to keep the items on the same line. For four columns, N would be set equal to ((RN/4)+1), and another PRINT statement would call for printing $$((3*N)+1).. Obviously, you’d have to adjust the tabs accordingly. SPRING 1981 Another command which helps to free us from the right margin is [SPC( )], which, as the name im- plies, involves spaces rather than tabulation. The TAB/HTAB family of commands uses the left margin as its baseline, measuring from there each time it is used. The SPC( ) command measures from the end of the previously printed statement. These next two statements will do precisely the same thing: 260 PRINT “A”,” muBr 270 PRINT “A”SPC(8)“B” Note that the SPC( ) command must be in a PRINT statement, that it does not require semicolons, and that the number of spaces must be in parentheses. SPC( ) also requires less memory than a string of blank spaces in your program. And, to make this complete, you can also SPC( ) to a variable, which means that this next line will duplicate lines 260 and 270 above, putting eight spaces between the “A” and the “B”: 280 X= 16 282 PRINT “A”SPC(X/2)“B” Remember, the SPC( )command measures from the end of the item preceding it, rather than HTAB or TAB's reference to the left margin every time they are used. The FLASH and INVERSE com- mands are used to highlight char- acters on the video screen (excuse me, the CRT display). They look good, if not overused. The most common programming error with them is forgetting to use NORMAL to return to good ‘ol white on black, but this one manifests itself very quickly. Thanks to the semicolon, we can highlight part of the PRINT statement, like this: 290 PRINT “YOU ARE ”;: INVERSE: PRINT “VERY WEAK”; :NORMAL:PRINT ” TODAY.” The INVERSE and NORMAL com- mands are set off by colons as se- parate statements in the program line. The PRINT command must be repeated after a colon, or else: APPLE ORCHARD. 300 PRINT “YOU ARE ”;:FLASH: PRINT “DEAD”;: NORMAL: PRINT “TODAY.” There is one aesthetic problem with FLASH: if it’s on the screen for more than a few seconds, it be- comes more of a nuisance than a help. Clear it out when it has done its attention-getting job. One good use for FLASH is for showing that the computer is occupied by an in- ternal activity for the moment, with a message like 310 FLASH: PRINT “WORKING. . .”: NORMAL INVERSE and FLASH affect only the Apple’s output to the CRT dis- play (excuse me, the video screen). Your input remains white on black. VERTICAL SPACING Remember, with the horizontal location process, that semicolons and [SPC) )] measure from the pre- viously printed character, while HTAB, TAB, and commas use fixed references measured from the left margin. Vertical location is also pos- sible from a fixed reference (the top of the screen) or a relative distance from the last characters PRINTed. We begin with the relative refer- ence; the applicable command is: 320 PRINT Yup; PRINT by itself allows you to skip a line. To skip three lines, type: 330 PRINT: PRINT: PRINT 335 2:2:2: —remembering that the question mark is a shorthand way of asking for [PRINT]. It's no more difficult than that. But sometimes, as when material scrolls upward off the 24-line screen, relative spacing doesn’t quite do the job. PAGE 11 Hence the need for a means of positioning or formatting material vertically. The primary means of do- ing this is VTAB, or vertical tabula- tor, which will place the first char- acter of your material a given num- ber of lines down from the top of the screen. So, 340 VTAB 5: PRINT “APPLE” will cause the word “APPLE” to be printed on the fifth line, at the left hand margin. Note, however, that whatever is on the screen from pre- vious [PRINT] statements will not be disturbed. This is a situation which could very quickly lead to clutter, but which also has advantages. Now, it is through the combina- tion of vertical and horizontal for- matting commands that we gain both flexibility and power. For ex- ample, given a blank screen, try this: 350 VTAB 5: HTAB 7: PRINT “COMPUTER” ~—and, if you RUN lines 340 and 350 together, you get both words properly placed, but by indepen- dent commands. Aha! That should suggest all kinds of flexible for- matting possibilities. The combina- tion of VTAB and HTAB allows you to place any characters anywhere on the screen. One example is: 360 VTAB 5: PRINT “NUMBER OF MEMBERS: ” (lines calculating the number of members) 370 VTAB 5:HTAB 20:PRINT M: REM M= MEMBERS What that means is that a data framework can be set up on the screen using commands like Line 360 above for the descriptions, and coming back later with commands like Line 370 to supply or to change the data. You can even do this: 380 VTAB 5:HTAB 20:INVERSE: PRINT “ ”;M;“ ” :NORMAL PAGE 12 —and you get the data in inverse, while the description is normal. (The spaces before and after the M are just to make the display look better). It’s not uncommon to use the top 15 screen lines as a form framework, while the prompts for inputting data occupy lines 16 through 24. Part of the screen can be made to hold still, or be “frozen”, by use of a [POKE] command. A [POKE] command?? Yup. As with any POKE command, we enter a location and a value, lowering the top of the screen from line 0 to another line between 0 and 23. The memory location is 34, so if you want the screen fixed in place above line 10, the command is: 390 POKE 34,9 ~and you can't print above line 10. Well, yes you can, by using VTAB to a line above line 10. But all of the text scrolling will take place below line 9 until you reset the window; try: 400 POKE 34,0: HOME and all is normal. In addition, loca- tion 34 (along with the other win- dows) can be cleared with: 405 TEXT That HOME reminds me of three commands which can be used to “erase” material already on the screen prior to installing revised data at the same screen location. Example: if we set: 410 HOME:VTAB 4:HTAB 5: PRINT “CIDER SQUEEZINGS” —we get the printed words on the fourth line down, covering the hori- zontal spaces from 6 through 21, as the string is 16 characters long. Now, we can try to replace the word “squeezings” with the word “press”, thus: 420 VTAB 4:HTAB 11:PRINT “PRESS” APPLE ORCHARD and we get—“CIDER PRESSZINGS’. Oops! The new word didn't erase all of the longer word that was there first. Well, we couldn't use HOME or CALL -936, or we'd clear the whole screen. Note: HOME is not available in Integer Basic; use CALL -936. Note to Note: THERE IS ONLY ONE “R” IN “INTEGER”! But we can use CALL -958, which clears only that part of the screen below and to the right of the cursor location. Or, if you have other material below the cursor, use CALL -868, which clears only the rest of the line on which the cursor is located. Like this: 430 VTAB 4:HTAB 11:CALL -868:PRINT “PRESS” Note that the [HTAB] precedes the [CALL]; you thus clear from the 11th space to the right margin. Now let’s say you have a list of data to be printed out on the screen, and the list has more than 24 items. Whoops—there go the first few items off the top of the screen, while you scramble to find CTRL-S to stop the runaway. Well, there is a better way. At least two better ways, in fact. Method 1: Set your PRINT routine up like this: * 800 REM PRINT ROUTINE 810 F=0: REM FLAG 820 FOR I= 1 TON: REM N= NO. OF ITEMS 830 (the data print statement for each line) 840 F=F+ 1: IF F> 22 THEN GOSUB 1000: F= 0: HOME 850 NEXT I 1000 INVERSE:PRINT “ PRESS [SPACE] TO CONTINUE... "3: GET A$: PRINT: NORMAL: RETURN This method increments a flag with each line printed. At Line 23, the subroutine is called. Pressing the space bar (or any other key) causes the PRINT routine to con- tinue in an orderly fashion, a screenful or “page” at a time. SPRING 1981 Method 2 900 REM ROUTINE 910 FORI=1TON 920 (the data print statement for each line) 930 IF PEEK (37)> = 22 THEN GOSUB 1000: HOME 940 NEXT I This one looks for the cursor loca- tion, at memory location 37. Find- ing the cursor at or below Line 22, it triggers the subroutine. You can, of course, set the values at other lines, to fit your format. A semi-digression (which is noth- ing like a trailer truck running off the road): you can vary your dis- plays by using the [SPEED] com- mand to slow down the rate at which characters appear. SPEED= 255 is both the fastest speed and the default value. .. what you normally see on your Apple is the “255” rate. The slowest rate is 0. Like [FLASH], the slower display rates are useful in small quantities, but become irri- tating after prolonged exposure. INPUTS AND GETS Having covered the means whereby PRINTed characters out- put by the computer can be liber- ated from the left margin, or the top of the screen, let's consider the characters input by you in answer to requests for information neces- sary to the execution of your pro- gram. Like this: 440 PRINT “YOUR NAME”;: INPUT A$ or 445 INPUT “YOUR NAME?”;A$ which are the two variations of this command. Now, as shown above, these lines will begin at the left mar- gin. You can move ‘em wherever you want ‘em. SPRING 1981 Note another wrinkle here. In Line 440, we used a PRINT state- ment for the prompt material, fol- lowed by the INPUT request. In Line 445, the prompt material is in- cluded as part of the INPUT re- quest. We didn’t put the question mark in Line 440, because the sys- tem does it automatically, since it didn’t find any prompt material in quotes. The INPUT request, when used as in Line 445, allows you to replace the question mark with any text you desire. In a format situation, you quite often want a number printed in the same position on the screen, even if it may contain different numbers of digits at various times. Don’t input a real or integer variable, INPUT a string, then use the VAL( ) function to derive the numerical value. If you hit a letter when the computer is expecting a number, it's error time. Having INPUT a string, you can use one of my favorite subroutines, which equalizes string lengths: 450 FOR K=1 to L% :IF LEN(A$) <L% THEN A$=” "+ A$ 451 RETURN Of course, you have to set L%to the maximum string length for that application, but you can use differ- ent lengths during the program. It looks like this: 460 L% = 4: GOSUB 450: PRINT A% = VAL(A$) The subroutine inserts blank spaces ahead of the INPUTed num- ber, then creates the Integer vari- able after printing the formatted string. (Yes, it could be a real vari- able too). The PRINT statement for a num- ber calculated by the computer can also be converted to a formatted string before PRINTing; in fact, there’s no law against using the A$ variable over and over, in conjunc- tion with Subroutine 450. A$ needs to retain a value only long enough to PRINT it, after which it moves on to the next number. APPLE ORCHARD 470 A$ = STRG(TL):L% = 4: GOSUB 20: HTAB 4: PRINT A$;:A$ = STR$(TM): L% = 6:HTAB 18:PRINT A$. The INPUT statement requires a [RETURN] after the data is typed, and we all know that a GET state- ment does not. That is, as soon as the info is typed in response to a GET statement, the microprocessor is off and running with it: 480 PRINT “ENTER INITIAL: ” GET A$ So a GET statement, while it is faster, is good for only a single- character response, right? Wrong. If you have a definite number of char- acters to be entered, try this: 490 PRINT “ENTER 3 INITIALS: "3: GET A$: GET B$: GET C$: D$ = A$+ B$+C$: PRINT D$ As an alternative, you can GET ina loop, as in: 495 PRINT “ENTER3 INITIALS: ”;: FOR I= 1 TO 3: GET A$: B$= B$+ A$: NEXT:PRINT BS Notice that you can’t do with GET what you can with INPUT as we showed in Line 445 above; you must use the PRINT statement. Note also, the absence of semi- colons between the GETs. Either ex- ample will pick up three characters, no more, no less. It combines the three single-letter strings into one three-letter string, and heads for the hills. ..or at least for the next pro- gram line. For many reasons, in- cluding some caused by quirks in the machinery, you're best off ac- quiring numerical answers by GET- ting string variables and converting to real or integer using the VAL( ) function. Finally, the most direct, and yet most sophisticated way to put a text character on the TV/CRT/VDU (Video Display Unit) screen is to POKE it there, directly into one of the 960 cells of the 40 by 24 “grid”. Try this: 500 HOME: POKE 1335, 195: POKE 1336, 201: POKE 1337, 196: POKE 1338, 197: POKE 1339, 210: POKE 1340, 160: 510 POKE 1341, 208: POKE 1342, 210: POKE 1343, 197: POKE 1344, 211: POKE 1344, 211 PAGE 13 How ‘bout that! What you've done, of course, is exactly what the Apple has been doing for you all through this article. You have first identified a location on the screen, and then placed a specific character in that location. The first number in the POKE command is the location for a par- ticular block on the screen, which is mapped out on Page 16 of the Ap- ple Reference Manual. Each of the 960 blocks on the screen has its own address in the Apple's mem- ory. We used the Figure to locate the address of the eleventh line for our example above (starting loca- tion in 1320 decimal or 528 in hexa- decimal), and then moved 15 spaces in from the left margin by adding 15 to the 1320 line starting address, to begin our word at loca- tion 1335. Look closely at that screen map; notice that the blocks are not num- bered consecutively, but rather in three horizontal bands of eight lines each. You can easily demonstrate this phenomenon: 520 HOME: FOR I= 1024 TO 2039:530 POKE I, 193: NEXT Which character goes into that lo- cation is determined by a numerical code; the American Standard Code for Information Interchange, or ASCII. (To pronounce “ASCII”, think of a donkey unlocking a door). The table on Page 15 of the Reference Manual shows the ASCII numbers for the characters available to you on the Apple. The ASCII code num- ber is the second number in the POKE command. Now try this: 540 HOME:POKE 1339, 220 That's a backward slash, and you won't find it on the Apple keyboard. The only way you'll get it on the screen is by POKEing it there, or by using the CHR$( ) function, which also involves the ASCII code num- ber, in a PRINT statement. There are a couple of other characters you'll not find on the keyboard, in- cluding the underline (ASCII 223) and left bracket (ASCII 219). For all characters, whether normal, flash- ing, or inverse, the POKEs give you direct access to the screen. PAGE 14 APPLE ORCHARD AN INTRODUCTION TO LIGHT PENS by Neil D. Lipson A.C. Software Chairman It has been brought to my atten- tion that there are many program- mers that do not know the opera- tion of a light pen. The operation is relatively simple. There are a few different types of pens out on the market, each of which functions dif- ferently. Hopefully, this article will help you in your understanding of the operation of these pens. There are basically three types of pens in use for the Apple. Those that use an on-off type of cell (typically a phototransistor), those that operate on resistance, and those that use an optodetector, sen- sitive to raster scan of a monitor. The most expensive (over $200) is the raster scan model. It picks up the actual scan on the monitor and uses this for determining the loca- tion of the point. Since this is far faster than the former two, it is fast enough to draw lines very quickly. However, to accomplish this, it must have some sophisticated elec- tronics and a rather large barrel, which accounts for the very high price of the unit. It can pick out very small points (hi-res), among other things. This is due to the focusing nature of the optodetec- tor. It must be very accurately ad- justed along with the monitor, or it will not operate correctly. The most popular light pens for the Apple, however, are those that use phototransistors, and cadmium sulfide and selenide cells. The phototransistor cell is somewhat faster than the cadmium cells, but does not do as much. It can detect only an on-off threshold. When us- ing it with a monitor or TV, the brightness and contrast must be ad- justed just right, or again, it will not always operate perfectly. This leads into another shortcoming of the cell, in that it cannot determine dif- ferent variations of light. Therefore, you cannot use software to deter- mine differences in light; only an on-off condition. This is fine if all you do is pick points from the screen with no change in light con- ditions. However, if the sun rises and shines through the window close to the monitor, you may end up readjusting the monitor. Also, suppose you want to use the pen to give variable readings instead of on and off? This is the reason for going to a cadmium sulfide. They will do both of these functions. However, a pure cadmium sulfide cell is very slow. The solution for this is to go toa high speed cadmium selenide cell. You then have the speed of a phototran- sistor, and the ability to read differ- ent levels of light. These cells are quite expensive, and the manufac- turer must choose very carefully a cell that fits all these parameters. What had to be done to satisfy these conditions, was to custom make -the cell to operate under these parameters. While this added to the expense of the light pen, it gave the user the ability to do every- thing he could want with a light pen. Pens of this type can act as light meters, and other applications which the regular phototransistor pens cannot do. The pen works differently for dif- ferent applications. To spot a point on the screen, it will check every point very fast, and look for a possi- ble match. When the point on the screen turns off, and the pen “sees” an off condition, it registers a possi- ble hit. It then verifies the point by turning it on and off, checking it SPRING 1981 everytime it does this. If after a few checks, it verifies, and then uses this point in the program. When the pen is used in drawing points, there are a few different methods used. One is to draw a “sheet” of light coming from the top down, and then from the left to right, and picking out the x and y coordinates. Another method is to scan the screen in bars, and localize which bar is being scanned. Another method is by using blocks of light. They are all satisfactory and give roughly the same end result. For those pens that use cadmium selenide cells, different levels of light can be detected, and used ac- cordingly. This type of pen is plugged into the game paddle into the pdl(0), pdl(1) or pdl(2) point. They simulate the paddle opera- tion. The resistance (if the cell is properly designed) is from 0 to 150K ohms. As the amount of light rises, the resistance drops. Even if the operation of the resistance is not linear, software can correct it. Hopefully, this will help you in your understanding of light pens and their operation. Screen Formatting of Text (continued from page 9) But all that POKEing is a tedious process for large amounts of text, which is why we have all of the other PRINT and formatting com- mands. But with the POKEs, you've just stepped out onto the path that leads to (gasp!) machine language. | suggest that you review the Apple II Reference Manual (spiral bound, 1979), Pages 14-16, in which the Figure and Table appear. While you're in the Manual, you can de- cide how much closer to machine language you'd like to get, by trans- lating the POKEs into “00’s through “FFs. As noted, if you find better ways, please let us know; and do your part to beautify the world’s CRT/ TV/VDT screens. SPRING 1981 APPLE ORCHARD PAGE 15 Make the Apple II* a powerful IEEE-488 Controller in asnap. Just plug the SSM A488 board into any Apple II* expansion slot for a low-cost, full-featured instrumentation interface. SSM gives the Apple II the power and versatility of a $9,000 IEEE-488 controller. At a fraction of the price. Our board converts the Apple II into a truly sophisticated controller that programs and controls up to 15 different instruments connected together on the 488 bus. ‘We make programming easy. The 68488 chip, designed by Motorola, forms the heart of our A488. We back this chip with powerful on-board firmware to give you system control via simple string commands. The only software you need is easy-to-program Applesoft* Basic. To develop special purpose firmware, simply replace our PROM with a RAM. With the A488, bus com- munications operate at top speed—without depending on software loops for timing. And like the more expensive IEEE-488 controllers, this system interfaces with more than 1200 instruments and peripherals. Suitable for OEMs as well as end users. Whether you make test/measurement systems for re- sale, or simply for yourself, the SSM/Apple combo gives you top performance. As it cuts your costs. Call your local dealer or SSM today for complete details. IEEE-488 bus cable (6 ft. with stackable connectors) Industrial grade circuit board PROM firmware for powerful user interface 68488 IEEE-488 controller chip- Slot-independent connection to Apple II EY EEF ae aw AU SSM’s A488 board expands the Apple II ti 's oard expands the Apple II to : a high-performance IEEE-488 controller. Be Eee orn utes Productsnlne: San Jose, CA 95131 (408) 946-7400 Telex: 171171 * Registered trademarks of Apple Computer In. TWX: 910-338-2077 PAGE 16 APPLE ORCHARD SPRING 1981 MR. RAINBOW presents our valuable free catalog (over 100 pages). He PROMPTS you to PEEK at the latest collection of software and hardware products for your APPLE II™ VERSAWRITER Il A drawing tablet, simply plugs into your game 1/0 port. Trace, draw, design, or color any type of graphic. Adds words to pictures. Creates schematics. Computes Distance /Area of any figure. New - fill any area on the screen in seconds with over 100 different and distinct colors. Needs 32K Applesoft ROM and disk drive. A bargain at... $249.95 A STELLAR TREK the definitive Hi-Res color version of the classic irtrek game. Three different Klingon opponents. Many command prerogatives from use of weapons to repair of damages. Needs 48K Applesoft ROM. Disk. ..$24.95 SUPER SOUND Musical rhythms, gunshots, sirens, laser blasts, explosions...add these and many more exciting sounds to your Apple. Use them in your programs, or create your own BOWLING DATA SYSTEM This data mangement program provides accurate record keeping and report generation for bowling leagues of up to 40 teams with bowlers per team. SUPER SOUNDS. Needs Needs 80-column printer, “6K Applesort. 32k Applegate ROM. Have a blast for only Disk...$78.95 $12.95... Tape $16.95...Disk ADD $2.00 U.S. $10.00 FOREIGN FOR SHIPPING CALIFORNIA RESIDENTS ADD 6% SALES TAX Open Tues. - Sun. Don't see what you want here, then write or call today for your free catalog. We're saving one just for you. GARDEN PLAZA SHOPPING CENTER 9719 RESEDA BOULEVARD DEPT. 12AO NORTHRIDGE, CALIFORNIA 91324 Visa/Mastercharge welcome. PHONE (213) 349-0300 SPRING 1981 APPLE ORCHARD PAGE 17 NOTES ON HI-RES GRAPHICS ROUTINES IN APPLESOFT Checking out the entry points given by J. Crossley in the article “APPLE- SOFT INTERNAL ENTRYPOINTS” in the March/April 1980 Apple Or- chard, | found the given entry points were 4 bytes off from the given ones in our APPLE II Plus. Fur- thermore, after checking out the routines in more detail, | thought to share my experiments with other APPLE II Plus owners interested in machine language programming. In the first section, | describe the essential data storage area, in the second | give the entry points of the subroutines somewhat more detail- ed than in the above article, and in the last section | give some listings of instructions following the entry points so that one could identify it for different versions of Applesoft. 1. DATA STRUCTURE There are four data in five mem- ory locations which specify a point on the high resolution screen (whether the screen is displayed or not, is irrelevant). | call these data collectively as external cursor data. The five memory locations, and their contents are as follows: $EO: Low order bits of the hori- zontal screen coordinate $E1: High order bit of the hori- zontal screen coordinate $E2: Vertical screen coordinate $E4: Color masking word from the color table ($F6F6- $F6FD) $E6: Page indicator ($20 for Page 1, $40 for Page 2) by C. K. Mesztenyi Washington Apple Pi | have called the above set of data as external cursor data since the ac- tual point plot is performed by the following five instructions: LDA $1C EOR ($26),Y AND $30 EOR ($26),Y STA ($26),Y which uses data located at $1C, $26, $27, register Y and $30. The contents of register Y are always picked up from location $E5 prior to the above instructions, thus we may call the data in the following five locations as internal cursor data: $1C: The color masking byte shifted for odd address and none black or white, un- changed otherwise. $27: (Low, high order) ad- dress of the byte corre- sponding to the page, verti- cal coordinate and leftmost seven points of the screen. $E5 (register Y): The integer part of the horizontal screen coordinate divided by 7. $30: The bit position taken from Bit Position Table corre- sponding to the remainder of the horizontal coordi- nate divided by 7. $26, These two cursor data (external and internal) are equivalent in the sense that given one, the other can be derived from it. There would be no need to make any distinction if they would correspond to each other all the time, but unfortu- nately, this is not always the case, e.g. the following sequence of BASIC instructions: HCOLOR=1 HPLOT 0,0 TO 10,10 HCOLOR =2 HPLOT TO 10,50 plots two lines, (0,0) to (10,10) and (10,10) to (10,50), both with color 1, ie. HCOLOR=2 has no effect. Actually it resets the color code in $E4 but it does not change $1C, and the statement HPLOT TO picks up whatever was left in $1C. A machine language programmer can write his/her own graphics rou- tines which takes time and uses sometimes much-needed memory space. Thus using the available pro- grams in Applesoft ROM can be ad- vantageous. If execution time is also important, as in the case of anima- tion, then one should concentrate only on the internal cursor data, and modify the external cursor only when it is necessary. The entry points INTX and INTY, provide the basic routines for incremental plot- ting which are not available directly in BASIC. Also, modifying the exter- nal cursor coordinates allows the use of HLINE with off-set. PAGE 18 2. ENTRY POINTS IN APPLESOFT Page and Color: HGR2 ($F3D8): Displays page 2 with all graphics mode, sets $E6 to $40, clears page 2 (black) and sets $1C to zero (black 1). HGR ($F3E2): Displays page 1 in mixed mode, sets $E6 to $20, clears page 1 (black) and sets $1C to zero (black 1). BKGND ($F3F4): Clears the page defined by $E£6 to the color defined by the con- tents of register A, which should be one from the Color Masking Table. Also stores register A in $1C. HCOLOR ($F6FO): Assumes regis- ter X contains the color index (0 to 7). The rou- tine picks up the appro- priate color code from the Color Masking Table and stores it in $E4. Positioning Entries: HPOSN ($F411): Assumes the in- put upon entry in the re- gisters as: register X= low order bits of the horizontal screen coordinate, register Y=high order bit of the horizontal screen coordinate, register A=vertical screen coordinate. The routine stores the re- gisters in $E0, $E1 and $E2. Then, using $E6, sets $26, $27, $30 and $E5 together with register Y, and sets $1C to the con- tents of $£4. Thus this routine makes the internal cursor equivalent to the external one. INTX ($F465): Modifies the internal cursor data in $1C, $E5, register Y and $30 so that it corresponds to incrementing/decre- menting the horizontal APPLE ORCHARD. screen coordinate X by one. Upon entry, if the N-flag is zero (positive) then it increments; if N is set (negative) then it decrements. The modi- fication has a wrap around feature, i.e., in- crementing/decrement- ing at the extreme sides of the screen defined by the internal cursor causes it to come back on the other side. The routine assumes that re- gister Y corresponds to $E5 upon entry, and leaves the routine cor- rectly modified if necessary. Upon testing the N-flag the routine jumps to DECRX or INCRX. DECRX ($F467): The routine modi- fies the internal cursor data by decrementing the horizontal screen coordinate by 1 (see INTX). INCRX ($F48A): The routine modi- fies the internal cursor data by incrementing the horizontal screen coordinate by 1 (see INTX). INTY ($F4D3): Modifies the inter- nal cursor data in $26, $27, so that it corre- sponds to incrementing/ decrementing the verti- cal screen coordinate by one. Upon entry, the N-flag is checked, and if it is set (negative) then goes to INCRY to increment by one, if it is not set (positive) then goes to DECRY to de- crement by one. Note that the sign convention is used opposite of INTX. These entries also have the wraparound features, i.e. if the in- crementation/decre- mentation causes the cursor to leave the screen on the bottom/ top, then it comes back on the top/bottom. SPRING 1981 DECRY ($F4D5): The routine modi- fies the internal cursor data by decrementing the vertical screen coordinate by 1 (see INTY). INCRY ($F504): The routine modi- fies the internal cursor data by incrementing the vertical coordinate by 1 (see INTY). IPOSN ($F5CB): Sets the external cursor data in $E0, $E1, $E2 equivalent to the in- ternal cursor coordinate data. Plotting Entries: HPLOT ($F457): Assumes input data in the registers as HPOSN: register X: low order bits of horizontal screen coordinate, register Y: high order bit of horizontal screen coordinate, register A: vertical screen coordinate. The routine calls HPOSN with the above data, then goes to PLOT. PLOT ($F45A): The routine exe- cutes the five instructions listed in the beginning of the article which plots a point using the internal cursor data. If this entry is used directly, then the user should make sure that register Y contains the data from $E5. HLINE ($F53A): The routine as- sumes input in the registers: register A: low order bits of horizontal screen coordinate, register X: high order bit of horizontal screen coordinate, register Y: vertical screen coordinate. (Note that it is in different order than (HPOSN.) SPRING 1981 The routine draws a line from the internal cursor position to the point de- fined by the input. Upon exit, it leaves the external cursor data corresponding to the input, the internal cursor data corresponding to the last plot point of the line. If the internal and external cursor data were not equivalent, then an off-set occurs. This can be visualized as follows: Draw a line segment from the external cursor coordinates to the input coordinates. Now move this line segment parallel to itself so that the end- point at the external cur- sor position gets into the internal cursor position. This is the actual line seg- ment which will be drawn. If it gets outside of the screen, then a wrap- around occurs, i.e. it comes back on the oppo- site side of the screen. APPENDIX The first few instructions are listed for each entry point so that one could identify them using the Moni- tor list feature. Bit Position Table: $F5B2: $81 = 10000001 $F5B3: $82 = 10000010 $F5B4: $84 = 10000100 $F5B5: $88 = 10001000 $F5B6: $90= 10010000 $F5B7: $A0= 10100000 $F5B8: $CO= 11000000 Color Masking Table: $F6F6: $00 =00000000 (black 1) $F6F7: $2A=00101010 $F6F8: $55=01010101 $FOF9: $7F=01111111 (white |) $F6FA: $80 = 10000000 (black 11) $F6FB: $AA= 10101010 $F6FC: $D5=11010101 $FOFD: $FF=11111111 (white I!) HGR2: $F3D8: BIT $C055 BIT $CO52 LDA #$40 BNE $F3EA APPLE ORCHARD HGR: $F3E2: LDA #$20 BIT $C054 BIT $C053 STA $E6 BKGND: $F3F4: STA $1C LDA $E6 STA $1B LDY $#00 HCOLOR: $F6FO: LDA $F6F6,X STA $E4 RTS HPOSN: $F411: STA $E2 STX $E0 STY $E1 PHA AND #$CO STA $26 IPOSN: $F5CB: LDA $26 ASL LDA $27 AND #$03 ROL ORA $26 INTX: $F465: DECRX: — $F467: BPL $F48A LDA $30 LSR BCS $F471 EOR #$CO INCRX: $F48A: LDA $30 ASL EOR #$80 BMI $F46E INTY: $F4D3: BMI $F505 DECRY: $F4D5: CLC LDA $27 BIT $F5B9 PNE $F4FF INCRY: $6505: CLC LDA $27 ADC #§04 BIT $F5B9 HPLOT: $F457: JSR $F411 LDA $1C EOR ($26),Y AND $30 EOR ($26),Y STA ($26),Y RTS $F53A: PHA SEC SPC $E0 PHA TXA SPC $E1 HLINE: PAGE 19 AN APPLE II QUICKIE by Gordon Stallings Tulsa Computer Society Here is a simple program which has been in use by the TCS Apple Users for the past year, and which should be more widely known: To copy a cassette tape from one recorder to another, you can use the Apple II as an intermediary to restore the signal levels. Recorder #1} “mon (playback) “in” Apple Ul “out” “mic” Recorder #2 (record) Put this program into the Apple II: 0000 20 FD FC JSR $FCFD 0003 AD 20 CO LDA $C020 0006 4C 00 00 JMP $0000 Start the program: *0G As long as this program is run- ning, any signal received from re- corder #1 will be sent to recorder #2. For best results, the following tips should be observed: 1. Be sure that Recorder #1 is set up to reliably read the tape which you are wanting to copy—volume, tone, and head alignment must be set so that the Apple can read the tape. 2. Recorder #2 should have cor- rect head alignment so that the new tape will be compatible with other machines. HOW IT WORKS The JSR calls subroutine $FCFD in the Monitor ROM, which watches the cassette input port waiting for a change of state, which indicates a zero-crossing on the playback tape. When the transition occurs, the subroutine RETURNS. The LDA $C020 toggles the cassette output port, recording a transition on the new tape. The JMP closes a pro- gram loop which can only be broken by RESET. PAGE 20 APPLE ORCHARD SPRING 1981 PRACTICAL SUPER HIRES GRAPHICS Bob Bishop's article in the Fall 1980 Apple Orchard serves its di- dactic purposes admirably in show- ing that resolution of 560x192 is attainable with Apple II. But the program he presents in his Fig. 4 has two substantial defects: it is slow, and it leaves occasional dark segments (particularly noticeable on a color TV monitor). Both problems can be alleviated by R. H. Good California State University Hayward, CA HPLOT successive vertical ments of steep lines as follows: seg- HCOLOR =3, HPLOT first segment; HCOLOR=7, HPLOT second seg- ment; increment x by Ty HCOLOR=3, HPLOT third seg- ment; HCOLOR=7, HPLOT fourth seg- ment; increment x by Note that HCOLOR=7 automati- cally plots things one-half x unit to the right of HCOLOR=3. A black line, HCOLOR=4, helps make the segments uniform. Here is Bishop's example again, with its two nearly-vertical lines, to which has been added a third line drawn by the improved procedures outlined above. with little trouble. The secret is to 1; and so on. 160 IF MZ = 2 THEN HCOLOR= 1 LIST 170 IF MZ = 3 THEN HCOLOR= 5 180 HPLOT X% / 29Y 5S REM 190 NEXT 200 PRINT CHRS (07)% REM BELL 220 REM LINE DEMO * RH GOOD 10 HGR 20 REN RHCOOD HPLOT 230 X = 150 40 PRINT CHR$ (7)$ REM BELL 240 D = 159 / 20 50 HCOLOR= 3 250 FOR Y = 0 TO 150 STEP It 60 HPLOT 13070 TO 140%156 260 HCOLOR= 4 70 PRINT CHR$ €7)$ REM BELL 270 HPLOT X + 3exY TOX + 39Y + DO cep | 280 HCOLOR= 7 100 REM 290 HPLOT X*s¥ TO XxY + D- 1 300 HCOLOR= 3 310 X =X +1 BISHOP 320Y=Y+5 330 HPLOT XsY¥Y TO Xex¥Y + D 110 FOR Y = 0 TO 156 340 NEXT 120 X% = 280 + Y/8 350 PRINT CHRS (07)! REM BELL 130 XX% = XX / 43MK = XX - 4 K XX 360 PRINT TABC 21)"HPLOT” x 370 PRINT TABC 22)"BISHOP” 140 IF M% = 0 THEN HCOLOR= 2 380 PRINT TABC 24)"R H GOOD" 150 IF MZ = 1 THEN HCOLOR= 6 390 CALL - 756: TEXT ¢$ END SPRING 1981 APPLE ORCH. IARD PAGE 21 sponse) by pppielBOrer qne BOSON, computer society apple Use Grour nnvee COM 1920, BONG tase. 02808 et) "361-8080 PAGE 22 APPLE ORCHARD SPRING 1981 COMPARING APPLESOFT PROGRAMS FOR DIFFERENCES In the July/August 1980 Call -A.P.P.L.E., Charles Boody wrote: “I often use programs that are published in various journals, and almost always find they lack some small (or sometimes some large) pieces that will make them more useful for me. Once I have made the changes or ad- ditions, | would often like to pass the changes on to others in the form of an article or list of changes. Unfortunately, it is dif- ficult to remember what 10 REM By Charles Boody, David W. Walker and Val J. Golding Call -A.P.P.L.E. changes have been made in which lines of what parts of which subroutines, and how those changes affect other parts of the program. | also often find myself with more than one ver- sion of a program; my own or public domain ones, that seem to have small differences that are very hard to trace down. Sometimes too, | find that | have kept several versions of a pro- gram under development, but am not sure about the detailed differences in them.” IST To alleviate some of those prob- lems, Boody wrote the COMPARE program. Subsequent to the publi- cation of the COMPARE program, we received a letter from David W. Walker who added some changes to the original program which he felt were significant changes, and we agree. In addition, Walker made several nice, but purely cosmetic changes. Interestingly enough, the form in which he submitted the changes to us was a printout pro- duced by the COMPARE program, which for us made the work of up- dating the original a breeze! COMPARE CAPTURER BY VAL J GOLDING 100 D$ = CHRS$ (13) + CHRS (4):0 PS = “OPEN"SWRS = "WRITE" SCL $ = "CLOSE"$ INPUT " PROGRA M NAME TO CREATE TEXTFILE FR OM ?P"SNAMESSFILES = NAMES + ".T"? PRINT DSsOP$"LIST."NAM ESsDSsWRS"LIST."NAMES? PRINT “LOAD” 3NAMES 110 DL$ = "DELETELIST."$TXTS = "3 TEXT? DELOsOtEND"iCMDS = "$HO MESPOKES3, 33¢LIST1-{"iCHS = “PCHRS( 4)" SPTS = "P"IC$ = "3 "3Q$ = CHR$ (34):ZERO$ = " Oo" + CHS + Q$ + OPS + FILES + QS + C$ + CHS + QS + URE + FILES + Q$ + CMRS + CHS + QS + CL$ + QS + C$ + CHS + GS + DL$ + NAMES + Q$ + TXTS 120 PRINT ZERO$$ PRINT "RUN"? PRINT D$"CLOSE” 130 PRINT D$"EXECLIST."NAMES" 100 REM COMPARE PROGRAMS ROUTINE BY CHARLES GC. BOODY ADAPTED BY DAVID W WALKER 110 DS = CHRS (13) + CHRS (4) PRINT D$"NOMONCIO” 120 COTO 2000 150 ONERR GOTO 810 160 GOTO 340% REM 200 REM GETS STATEMENT FROM THE OLD FILE 210 LET OS$ = ""$ PRINT DSs"READ "30% 220 GET A$? IF AS < > CHRS (13 ) OR LEN (0S$) = 0 THEN IF LEN (OS$) < 255 THEN OS$ = OSs + A$$ GOTO 220 230 RETURN SPRING 1981 The COMPARE program requires that you first write your object pro- grams to a text file which it can read. This is handled entirely auto- matically by our COMPARE CAP- TURER, which requires only that you supply it with the name of the program you wish to create a text file from, and that this program has no line numbered zero. The CAPTURER program will first create a temporary text file named “LIST. FILENAME", which it will later delete when it has served its pur- pose. CAPTURER then EXECs this file, which in turn lists the BASIC program to a text file named “FILE NAME.T”. When the “old” and “new” files have been created, just run the COMPARE program, which will ask you for the names of the old and new programs. The suffix “.T” should not be added; COMPARE will do this itself. It should be noted that program lines longer than 255 characters will APPLE ORCHARD be truncated by the COMPARE pro- gram, and that certain control char- acters may produce unexpected events.- For example, a REM line which contains a Control M, [Car- riage Return] (such as in the COM- PARE program itself) will result in COMPARE believing that the data following the Control M is a separ- ate program line, even though there is no line number. Printer protocol is established in the group of lines commencing at 1000, and line 1110 assumes you have a printer card requiring a Con- trol |. In both lines 1110 and 1120, the variable establishes a default of 70 characters per line for the printer. This may be changed to suit your specific needs. That the program works is at- tested to by a page of sample out- put, which compares “CREATE3” (an early version of the EXEC file writer) and “COMPARE CAP- TURER’, the final version. PAGE 23 When entering COMPARE CAP- TURER, it would be a good idea to not enter the extraneous spaces in the latter half of line 110, or a“TOO. LONG ERROR” may result. The CAPTURER should also serve as a reasonably well written example of how to write a text file that writes a text file. Q$ is set to equal CHR$(34), the double quote (”), and is used when required to place a PRINT statement within a PRINT statement. We have preferred to keep this type of shenanagin to an absolute minimum by almost entirely using strings instead of PRINT statements. The strings are defined in line 100 and in the first part of line 110, while the latter part of 110 is almost exclusively concatanenation. ZEROS$ is the villain in this one, as it is later EXECed into the object pro- gram and run, causing the object program to list itself to the second text file. \) aap fet, San Rafael, CA 98901 (416) 454-6500, 250 REN GETS STATEMENT FROM THE NEW FILE 260 LET NS& = ""% PRINT D$s"READ "SNS 270 GET AS? IF AS < > CHRS (13 ) OR LEN (NS$) = 0 THEN IF LEN (NS$) < 255 THEN NS$ = NSS + AS? GOTO 270 280 RETURN Finally 300 REM PRINTS A STATEMENT WITH A LINE LENGTH OF LL 310 Il = 0 320 10 = 3699% PRINT MIDS (J$%»TOrLbL) : IF II < LEN (J$) THEN 320 330 RETURN 340 PRINT D$"GPEN"0$5D$"OPEN"NS 350 GOSUB 2103 GOSUB 260: REM rotation 355 IF LEFT$ (0S$91) = CHRS (1 3) THEN OS$ = RIGHTS (OS$» LEN €O0S$) - 1) 360 IF LEFT$ (NS$91) = CHRS (1 3) THEN NS$ = RIGHTS (NS$» LEN (NS$) - 1) TT + 281% = 1 + Lei POKE ‘The Hires Baseball that's as good as the Apple! by Arthur Wells $24.95/32K/Disk/Applesoft or Integer we 8different pitches, 6 different + Player controlled fielding and throwing + Vocal umpire boar + Beautiful stadium in fullcolor A great hi-res lunar lander, just lke the arcade game! by Bill Budge creator of Trilogy and Penny Arcade $24.95/48K/Disk/Applesoft or Integer + Landscape scrolling + Auto-zoom for landing site close-up + Player control of 360° craft + Spectacular crashes + Always challenging Improve your scores 2s you improve your skill al. Residents Add 6% Soles Tax. NoC.O.D's Add $2.00for Shipping “Handling. Use Check, Money Order, VISA or MASTERCARD. (We ‘ed expiration date on charge card.) DEALER INQUIRIES INVITED. APPLE ia rete radar of Ae Computer, PAGE 24 APPLE ORCHARD Computer Station 12 Crossroads Plaza Granite City, IL 62040 (618) 452-1860 COMPUTER STATION proudly offers a high-speed binary video digitizer for the Apple Il called the DITHERTIZER II. The peripheral board uses a video camera with external sync to load the hi-res page of the Apple with any image the camera can capture. The DITHERTIZER Il is a frame grab- ber, DMA type digitizer requiring only '/,th of a second to capture a binary image. Software supplied with the board enables building dithered images and capturing image inten- sity contours. Intensity and contrast are user controllable via the game paddles. Matrix size for dithering changable with one keystroke. Requires video camera. With external sync; recommended model, Sanyo VC1610X. DITHERTIZER Il, $300; B/W SANYO VIDEO CAMERA, $410; PACKAGE OF DITHERTIZER Il AND CAMERA, $650. GRAPHIC DUMPS: COMPUTER STATION offers the highest degree of human engineering on the market for hard copy graphics from the hi-res pages of the Apple. The follow- ing machine language dump routines are available for BASIC: 1DS440G/445G° 1DS460G* ANADEX 9501 NEC SPINWRITER 5510 NEC SPINWRITER 5520 * Also availabe for use with Pascal, $44.95. GRAPHICWRITER: Hard copy of character sets found in DOS Tool Kit for use with Applewriter or print statements in your own programs. Requires DOS 3.3, DOS Tool Kit, one of graphic printers below: Silentype $34.95 1DS440G /445G 34.95 IDS460G 34.95 VISILIST: Get hard copy of the FORMULAS used in VISICALC models. Prints grid location, contents (formulas or labels). and giobal parameters. Handy utlity for all VISICALC users. 95 PROGRAMMER'S GUIDE TO THE APPLE, it a Thiel reference card (40 page booklet). $4. PROGHAMMERS HANDBOOK TO THE APPLE I: Send or call for free catalog. Apple Il is a registered trademark of Apple Computer, ISICALC is a Mentored iradersnn of Personal Software, Ine. DITRERTIZER Ils regered trademark of Computer Stations, Inc. SPRING 138592 400 REM IF BOTH STATEMENT NUMBER AND CONTENTS AGREE» THEN IGNORE 410 IF VAL (O0S$) = VAL (NSS) AND OS$ = NS$ THEN 350: REM 500 REM IF LINE NUMBERS ARE THE SAME BUT CONTENTS DIFFER» THEN PRINT *CHANGER” ANDI GET NEXT STATEMENT 510 IF VAL (OS$) = VAL (NS$) AND ass < > NS$ THEN PRINT $ PRINT "CHANCED "533% = O0S$$ GOSUB 3103 PRINT "TO "533% = NS$% GOSUB 310% GOTO 350% REM 600 REM IF OLD LINE NUMBER < NEW LINE NUMBER THEN OLD LINE IS DELETEDS FETCH NEXT OLD LINE 610 IF VAL (OS$) < VAL (NS$) THEN PRINT $ PRINT “DELETED "s$iJ $ = OS$! GOSUB 310% GOSUB 21 0: GOTO 410: REM 700 REM IF NONE OF THE ABOVE, THEN THE NEW LINE IS ADDED. PRINT “ADDED” AND FETCH NEXT NEW LINE 710 PRINT “ ADDED "s3J$ = NS$3 GOSUB 310% GOSUB 260: “GoTo 4103 REN 800 REM WHEN ONE FILE IS EXHAUSTED> DETERMINE WHICH AND INDICATE REMAINDER OF OTHER "ALDED" OR "DELETED"» AS CASE MAY BE 810 X = PEEK (218) + PEEK (219) x 256% POKE 21620% ONERR GOTO 910 820 IF X > 230 THEN 840 SPRING 1981 830 840 850 900 GOSUB 260% PRINT $ PRINT "AD LEDS"53J$ = NS$$ GOSUB 310% 830 IF VAL (OS$) < > VAL (NSS ) THEN PRINT $ PRINT “DELET ELDS"s3J$ = OS$$ GCOSUB 310 GOSUB 210% PRINT $ PRINT “DE LETEDS"stJ$ = OS$i GOSUB 310 3 GOTO 850% REM GoTo REM ASSUME END OF DATA ERROR IN LAST 910 1000 FILE AND END PROGRAM PRINT $ PRINT "END OF COMPAR ISONS":$ PRINT D$"CLOSE"DS$"PR 30" END $ REM REM PRINTER SUBROUTINES 1010 1020 1030 1100 1110 1120 2000 2010 2020 2030 2040 2050 2065 2070 2080 PRINT “PRINTER OR CRT? "5% GET PRS: PRINT PRS IF PR& = "C* THEN PR = O&LL = 30% RETURN INPUT "ENTER PRINTER SLOT 0 R CALL “sPR% RETURN IF NOT PR THEN RETURN IF PR < 8 THEN PRINT DS"PR $"3PR3 PRINT CHRS (9)5 CHRS (26)8LL = 703 RETURN CALL PR? PRINT CHR (26 )3L L = 70% RETURN $ REM TEXT ¢ PRINT HOME $ PRINT ¢ TI$ = " PROGRAM COMPARER ° HTAB 20 - LEN (TI$) / 22 INVERSE 3 PRINT TI$? NORMAL PRINT $ PRINT PRINT ” This Program wi 11 compare two ver- sions of 3 Program and produce 2 lis t ofthe differences between them. "5 PRINT "Both Programs mu st be in textfiles# use the Program " CHRS (34 "COMPARE CAPTURER.” CHRS (34) PRINT $ PRINT "What is the name of the OLD version?” INPUT 01$%0$ = G16 + ".T” PRINT $ PRINT “What is the name of the NEW version?" INPUT N1$3NS = N1S + ".T" APPLE ORCHARD. PAGE 25 2085 PRINT $ INPUT “What is toda w’s date? “sDTS PRINT $ PRINT ¢ HOME $ VTAB 9 IF PR THEN PRINT "MAKE SUR E THE PRINTER IS READY» THEN « 2090 GOSUB 1000 2100 2110 2120 INPUT * HIT CRETURNI TO RUN "sXX$ 2130 TEXT ¢ HOME 2140 GOSUB 1100 2150 XX$ = “KkEK COMPARISON OF *& wx" 2160 GOSUB 2500 2170 PRINT %XX$ = 01$% GOSUB 250 ° 2180 PRINT %XX$ = "and" GOSUB 2 500 2190 PRINT %XX$ = N1$i GOSUB 250 0 2200 PRINT $ POKE 36740 + 40 & (¢ PR > 0) - (10 + LEN (BT$))3 PRINT “Prerared? *BT$! GOTO 150 POKE 369(20 + 20 & (PR > 0) ) - LEN (XX$) / 2% PRINT XX $3 RETURN 2500 KEYBOARD RECORDER This program generates a keyboard file by monitoring and recording keyboard input. It can be used together with the System Monitor, BASIC or DOS, and is transparent to other programs receiving the input. The keyboard file can be selectively played back in a similar manner as the disk EXEC command to avoid repeated typing of the same input. A user may review the file on the screen, or save and load the file by using tape or disk. It saves time and storage space during pro- gram development and revision by keeping rec- ords of program changes or doing automatic pro- gram testing. DISKETTE OR CASSETTE: $25.95 (with docu- mentation; specify DOS 3.2 or DOS 3.3 for disk) SINGLE DRIVE DISK COPY This program makes disk copying easy and er- ror free. It uses only one disk drive to copy some or all sectors on the disk. DISKETTE ONLY: $11.95 DOS 3.3, APPLE II or ll+) (specify DOS 3.2 or Zeus Computing, A1 P.O. Box 712 Downey, Ca. 90241 PAGE 26 APPLE ORCHARD SPRING 1981 *5%% COMPARISON OF *2x% CREATES and COMPARE CAPTURER Prepared: 2/8/81 ADDED 10 REM ADDED COMPARE CAPTURER BY VAL J GOLDING CHANGED 100 DS = CHR$ (13) + CHRS (0)% INPUT “PROGRAM NAME TO CREATE TEXTFIL E FROM "SNAMESSFILES = NAMES + “.T"% PRINT DS" OPENLIST. ”"NAMESSD$"WRITE LIST."NAME$! PRINT “LOAD” sNAMES To 100 D$ = CHR$ (13) + CHRS (4):0P$ = “OPEN"SWRS$ = “WRITE” SCL$ = “CLOS €"t INPUT © PROGRAM NAME TO CREATE TEXTFILE FROM 7°$NAMESSFILES = NAM £$ + ".T"$ PRINT DSFOPS$"LIST."“NAMESSDSSWRS"LIST.°NAMES$ PRINT "LOAD" 5N AMES CHANCED 110 Q$ = CHRS (34)3CMDS = “OPEN"SZEROS = " 0 DS=CHRS( 13 )+CHRS( 4 )3PRIN TDSs" + QS + CMDS + FILES + QSiCMDS = "WRITE" $ZEROS = ZEROS + “SPRINT DSs" + QS + CMDS + FILES + QSiCMDS = "CLOSE" $PRNT$ = " PRINT " + CHRS (34) To 110 DL$ = "DELETELIST."$TXT$ = "STEXTSDELO*sO%END"SCMD$ = " SHOMESPOKE33 s33tLISTI-3"8CHS = "“PCHRSC4)"SPTS = "“P"SCS$ = “$"3Q$ = CHRS (343 ZEROS =" 0" + CHS + QS + OPS + FILES + QS + C$ + CHS + GS + WRS + FILES + Q$ + CMDS + CHS + Q$ + CL$ + GS + CS + CHS + ADDED Qs + DLS + NAMES + Q$ + TXTS CHANGED 120 ZEROS = ZEROS + “SHOMESPOKE33s33:LIST:" + " PRINT DS" + QS + CMDS + QS + “STEXT{PRINTDS” + Q$ + “DELETELIST.” + NAMES + Q$ + “3END" TO 120 PRINT ZEROS: PRINT “RUN"$ PRINT D$"CLOSE” CHANGED 130 PRINT ZEROS! PRINT "RUN"? PRINT * 0” TO 130 PRINT D$"EXECLIST.“NAMES" DELETED: 200 PRINT D$"CLOSE" DELETED: 210 PRINT D$"EXECLIST. "NAMES" DELETED: 220 END END OF COMPARISONS SPRING 1981 APPLE ORCHARD 2 SIDED DISKS Edited by D. Buchler of Mini’App’les from material supplied by Dysan Corporation Reversing Media on Single Head Flexible Disk Drive Flexible Disk Drives (floppys) of- fer the end user low cost random access to data records. Prior to the introduction of the floppy, the only other alternatives were sequential tape cassettes, low cost one-half inch tape, or single cartridge hard media disk drives. The floppy disk has been an ideal peripheral for low cost systems. There has been a tendency by some end users to economize by at- tempting to use the media on both sides in a single head drive. We most not lose sight of the fact that the value of the data stored on diskettes exceeds the cost of the media by a wide margin. Loss of data on either read or write means time delays, reconstruction of lost data, and customer dissatisfaction with the system, drive and/or manu- facturer. All of this can be avoided in advance if the end user is made aware of the whys and why nots. Head Shoe and Pad operation — The relationship of the head to the media is such that when the jacket is properly inserted, and all interlocks are satisfied, the head is loaded on to the media on the recording side, and a felt loading pad is applied to the non-recorded side. In a Shugart disk drive this is the top of the disk. In normal opera- tion, a gradual build up of oxide will accumulate on the pressure pad. There might even be some wear on the non-recorded side due to a scouring action of the oxide impregnated pad. If the media is reversed, that is turned up side down, the scouring action will now occur on the prime recorded side, and the previously scoured side is now presented for recording. The recorded data is now subjected to an abrasive wear- ing by the contaminated load pad. Since this data is not being read, there is not any means of detecting the amount of wear or the loss of data. While a catastrophic failure might not occur, it is possible that some drop out or other read errors might go undetected. Worse yet, is the possibility that the error condi- tion might be intermittent, which makes the entire operating system suspect. Another adverse effect of revers- ing the media is caused by reversing the direction of rotation of the media against the jacket. This re- versal of direction is apt to “break off” any build up of oxide particles. This presents a potential loose con- taminant situation. The net effect of this reversing (or flipping) action over a period of time, is to reduce performance and increase the probability of drop outs and errors. Diskette tensioning On most Floppy Disk Drives, when the diskette is properly in- serted and operation has begun, pressure is applied to the jacket on both sides so that proper tension is created on the flexible media prior to the recording head. This also provides a wiping action of the liner material against the flexible media. When the jacket is reversed, or flipped, the direction of rotation is reversed, breaking loose any extra- neous particles built up by prior wiping. Thus, reversing the media increases the probability of extra- neous contamination and again in- creases the probability of errors. PAGE 27 Two head Drives The above problem areas do not occur on two-head drives that are designed for two-sided applica- tions. On a two-head drive, the pressure pad has been replaced by a second head mounted on a ceramic shoe. The operation now consists of a head-media-head rela- tionship. The soft pressure pad with possible oxide build up has been eliminated. The diskette tensioning apparatus is the same on one and two-head drives. Since media spin direction is not reversed by flipping, the oxide break off problem does not occur. Summary The foregoing summarizes the reasoning why Dysan and major OEM suppliers of diskette drives do not recommend two-sided media for one-head drive operation. Dysan feels the potential operating problems would make an unwar- ranted reflection on its reputation by using media in an unsuitable fashion. When IBM introduced the 3740 diskette, they intentionally in- terlocked reversal possibilities by offsetting the index hole from the centerline. IBM does not make a reversable diskette. DYSAN does test and supply two-sided media for operation in two-head (two sides) disk drives. Note that the standard diskettes are not certified for opera- tion in two-head drives! Some club members have re- ported problems in using both sides of a diskette. While those problems cannot be proven to be related to any of the above types of occur- rences, it would seem wise to fol- low DYSAN’s advice. Members have argued that the manufacturers are trying to sell more disks. How- ever, not one of them has come out and recommended two side opera- tion or even sold diskettes with two slots cut. Another argument heard frequently is that the member is us- ing the second side for backup. Well you might get away with it, but | challenge anyone to religiously avoid using that reverse side except for the occasional update to create the backup. | myself plan to stick to one side from now on. PAGE 28 APPLE ORCHARD S. H. LAM ROUTINE UTILITY by Lee Reynolds Call -A.P.P.L.E. staff writer S. H. Lam’s Routine to set up ma- chine language routines within a BASIC program has been used by various authors submitting to CALL -A.P.P.L.E. and other magazines. The usage of this routine is best covered in the article “Hiding Out in Basic”, by Val Golding, in the June ‘79 issue of CALL -A.P.P.L.E. | have often used this routine my- self in my own programming. My usual method has been to: (1) create the machine code using my assembler, (2) assemble it into memory, and (3) go into the Moni- tor and laboriously copy down the hexadecimal values to be passed to Lam’s routine in a string. Recently, however, | thought: why not let my computer save me some energy in step (3) above? This is my justifica- tion for the program whose listing accompanies this article. The pro- gram will automatically create a Text File containing the necessary statement(s) to call Lam’s routine after setting up the string or strings it requires. The format of these state- ments in the Text File is: (linum) A$ = (monitor string): GOSUB (1st linum - 10) CALL - 144 The value of (linum) above is asked for by the program, which will also ask the name of the binary file to BLOAD, BLOAD it, and as- 10 REM SoH. BY LEE REYNOLDS CALL -A.P.P.L.E. LAM ROUTINE UTILITY SPRING 1981 sign a “.T” suffix to the name of the Text File to be created. If more than one BASIC statement must be generated to process the machine language code, then sub- sequent line numbers increase by 10. (You could change this, if you wish, by modifying line 470.) After you've used the program to create this Text File, you now need only EXEC it into your program that uses the machine language routine. You will note that the name of the string variable passed as an argu- ment to Lam's routine is A$. You could change this also, by modify- ing two lines in my program, namely 410, 430 and 470. (If you use Lam's routine in an Integer Basic program, remember that you must DIMension the string variable. As the program stands now, the maximum length of the string is 96 characters—not counting the extra 8 characters added on by Lam’s routine.) All functions are fully automatic, other than the specification of the line numbers to be assigned. The program will BLOAD the machine code, determine the starting ad- dress and length, write and save the Text File. | hope that you will find this utility of value in your future program- ming. STAFF WRITER 100 DIM HD$(16):D$ = CHRS (13) + 210 MEMSIZ = PEEK (978)3MEMSIZ = CHRS (4):Q% = CHRS (34) (MESIZ + 13) & 2562MEMAD = M 110 GOSUE 700: GOTO 200 EMSIZ + 114tA1 = PEEK (MEMA 120 J = INT (BYTE / 16)3HEX$ = H D) + PEEK (MEMAD + 1) & 256 D$(J + 1933 = BYTE - 16 * J3 SMEMAD = MEMAD - 18tA2 = Al + HEX$ = HEX$ + HBSC(J + 18883 ( PEEK (MEMAD) + PEEK (MEMA RETURN D+ 1) ® 256) 130 BYTE = INT (I / 256)! GOSUB 220 VTAB 8$ INPUT "BINARY FILE N 120% RETURN AME? “SFILE$! VTAB 10% INPUT 140 BYTE = I - 256 * BYTE: GOSUB “BEGINNING LINE#? "SLINES{SU 120% RETURN BS = LINES$LINE = VAL. (LINE 150 PRINT $ PRINT ¢ INVERSE $ HTAB $) + LOSLINES = STRS (LINE) 83 PRINT " HIT ANY KEY TO CO NTINUE "$ NORMAL $ CALL - 7 563 HOME : RETURN 200 DATA "OMe" 1M 9 223% ohh "Ss BM 7 MBM Oy" AM @B™ "CT *o"D",s"E"e"F"3 FOR I = 2 TO 230 PRINT D$"BLOAD*FILEStFILE$ = FILES + *.T" 16% READ HD$C I): NEXT I SPRING 1981 400 ADDR = A2tI = Al? GOSUB 13034 = HEX$3 GOSUB 140tA1$ = A 16 + HEX$ 410 X$ = LINES + " AS= "+ QS TA 1$ + "3"tL = LEN (X$) 420 PRINT DS*GPEN"FILES#DS" WRITE “FILES 430 RTS = QS + "NIB2ZIC" + QS PRINT " “SUBS5" AS=AS+"RT$"$ FOR I = 1 TO LEN (A$)% POKE Sit + Ivy ASC ( MIDS (ASoTs1)) + 128% NEXT 3 POKE 7220: RETUR Nn?" 440 FOR ADDR = Al TO A22¢BYTE = PEEK (ADDR): GOSUB 120:X$ = X$ + HEX$ +" "3L =L + 3% IF L < 100 THEN 490 450 X$ = X$ + QS + “$GOSUBR" + SUB $ + "SCALL-144"% PRINT X$ 460 IF ABDR = A2 THEN 500 470 LINE = LINE + 10%I = ADDR + 1 $ GOSUB 130:X$ = STRS (LINE >+ " AS= " + QS + HEX$? GOSUB 140 480 X$ = X$ + HEX$ + "f"3L = LEN (x$) 490 NEXT ADDRiX$ = X$ + QS + "3G GSUBY + SUBS + "$CALL-144"%% PRINT X$ 500 PRINT D$s"CLOSE"$FILE$$ END 700 HOME $ PRINT "S. H. LAM ROUT INE UTILITY"? PRINT $ PRINT “THE LAM ROUTINE IS A WAY OF STORING A MACHINE LANGUAG E ROUTINE INTO MEMORY FRO M INTEGER BASIC OR APPLESOFT + SEE THE ARTICLE “Q$"HIL ING QUT IN BASIC"Q$" IN" 710 PRINT “THE JUNE ‘79 CALL —-A. P.P.L.E. YOU COULDWRITE A T EXT FILE CONTAINING THIS ROU T- INE» THEN EXEC THE FILE I NTO A PROGRAM." PRINT $ PRINT 720 PRINT “THE PRESENT PROGRAM W ILL LIKEWISE CREATEA TEXT FI LE CONTAINING THE LINES NEED ED TO EXECUTE THE LAM ROUTIN Ey AS WELL AS STORE THE STR INGS THAT IT REQUIRES." GOSUB 150 APPLE ORCHARD PAGE 29 730 NORMAL $ HOME $ HTAB 6% PRINT "TO USE THIS UTILITY!" PRINT $ PRINT " 1. BLOAD YOUR MACH INE LANGUAGE ROUTINE INTO M EMORY BY ENTERING THE FILE N AME." PRINT ¢ PRINT " 2. EN TER THE STARTING LINE NUMBE R TO BE USED RY THE EXEC F ILE." 740 PRINT $ PRINT " 3. EXEC THE NEWLY CREATED FILE INTO YOUR PROGRAM AND ENTER A LIN E THAT WILL GOTO THE SE COND LINE OF THE LINES CREA TED BY THE EXEC FILE.” 750 PRINT $ PRINT "NOTES AS IS THE NAME OF THE STRING USEDI N THE EXEC FILE» AND MAY EAS ILY BE CHANGED. LINE NUM BERS IN THE EXEC FILE WILL BE INCREMENTED BY 10." GOSUB 1503 RETURN 900 REM BY LEE REYNOLDS & VAL J GOLDING APPLE 8 DEV MATE Now includes the Simplified Text Processor (STP) For 32K PET, disk 48K APPLE II 3.0 or 4.0 ROMS or —OR— or APPLE Ii + 8032 (specify) and DISK I MAE FEATURES — Control Files for Assembling Multiple named source files from disk — Sorted Symbol table — Up to 31 chars./label — 27 Commands, 26 Pseudo-ops, 39 Error Codes — Macros, Conditional Assembly, and a new feature we developed called Interactive Assembly — Relocatable Object Code — String search and replace, move, copy, automatic line numbering, etc. STP FEATURES = 17 text processing macros — Right and left justification — Variable page lengths and widths — Document size limited only by disk capacity — Software lower case provision for APPLE I without lower case modification ALSO INCLUDED. — Relocating Loader — Sweet 16 macro library for APPLE and PET — Machine Language macro library — Sample files for Assembly and text processing — Separate manuals for both APPLE and PET PRICE —" MAE, STP, Relocating Loader, Library files, 50 page manual, diskette —'$169.95 SEND FOR FREE DETAILED SPEC SHEET The Most Powerful Disk-Based Macro Assembler/Text Editor Available at ANY Price EASTERN HOUSE SOFTWARE 239 LINDA DR WINSTON-SALEM. NUC.27106 (919) 924.2889 (919) 748-8446 PAGE 30, Let me start by saying that | think the Silentype printer is potentially one of the most versatile printers on the market. Most conventional printers available for the APPLE control the printer operation via microprocessors in the printer with the printer functions coded in ROM. These instructions that tell the printer how to operate are hid- den from the user, and in fact are unalterable by the user. You can only do as much as the manufac- turer will let you do. The Silentype on the other hand uses the microprocessor in the APPLE to control the printer func- tions with the instructions con- tained on a ROM on the printer in- terface card. What this means to the user is that the hardware functions of the printer (i.e. moving the print- head, printing a dot, and advancing the paper) are all controllable di- rectly by the APPLE! We are no longer tied to the software provided by the manufacturer and are free to do anything we want within the mechanical constraints of the printer mechanism. WOOPIE! Our only problem now is to find out how to control the functions of the printer. Well, APPLE “thought- fully” didn’t provide any information on the ROM software or the printer hardware to allow this. Letters to APPLE didn’t produce any results either. Enter Sandy Greenfarb. Sandy also was trying to get infor- mation on the printer and obtained through IAC (International Apple Core) a 14 page writeup* on how to move the head and print a dot, and *See p. 43 Winter Apple Orchard “Inside the Silentype Firmware”. === APPLE ORCHARD FOR THE SILENTYPE by Bruce F. Field Washington Apple Pi also a little on how the printer char- acter set is defined and used. Just what | wanted. The result is the ma- chine language routine presented here for printing either Hi-res graphics screen at double size. Using the routine is very simple; it uses the standard Silentype para- meters to control the printing. You simply BLOAD the DBL GRAPHICS routine into memory (it resides from $300 to $3C7 and so won't conflict with Applesoft, Integer Basic, or DOS). You can generate or load your hi-resolution picture either be- fore or after loading the DBL GRAPHICS routine. Then initialize the Silentype as you would nor- mally (PR#1 from BASIC if your printer is in slot 1) and set up the printer parameters as desired. In- stead of typing a control-Q to print the Hi-res screen, from BASIC you CALL 768 to activate this routine. The CALL can be placed inside a program or typed directly from the keyboard. If you are typing the CALL from the keyboard and don't want those words to appear on the printer, first reset the APPLE output to the screen (PR#0); the printer does not have to be “turned on” to print the graphics. As it is written, the routine is slightly slot dependent and assumes your printer interface card is plugged into slot 1. It is very easy to change this if you use a different slot. The offending byte is at $30F hex or 783 decimal. This should be changed to $C0+printer slot (hex) or 192+ printer slot (decimal). Once you do this, you can save it back to disk and not worry about it. For those of you who are old hands at the APPLE and know how SPRING 1981 DOUBLE-SIZE GRAPHICS the Hi-res graphics screen works, you can go on to the next article; otherwise I’m going to try to de- scribe how the routine works. First let me air a pet peeve. Most double size graphics printing routines | have seen (as for the Paper Tiger) chop off the sides of the screen when printed full double size be- cause the picture is a little too wide for the printer. This comes about because the characters on the APPLE screen are 5 dots wide with a 2 dot space between them. Forty characters on the screen means 280 dot positions in the horizontal di- rection which is exactly the resolu- tion of the Hi-res screen. Most dot matrix printers however, print char- acters 5 dots wide with a one dot space between. For 80 column wide printers this means 480 dot positions, not quite enough to print the graphics double sized. The ob- vious solution (at least for me) is to print the graphics screen sideways on the printer! The vertical resolu- tion of the Hi-res screen is 192, times 2 is 384 which easily fits on a printer with 480 dot positions. So, guess which way my routine prints the screen? Now that | have that off my chest, let's dig a little deeper into how the routine works. A rather poor map of the Hi-res screen is shown on page 21 of the new APPLE Reference Manual. (It would be handy to get it out now for reference.) This map shows an array of 40 boxes in the horizontal direction and 24 in the vertical direction. In the horizontal direction, each box controls 7 dots on the graphics screen. As ex- plained on page 19 of the manual, bits 0 through 6 control the seven APPLE ORCHARD PAGE 31 The tricks our IBMS software can make your Apple* do! The small businessman has never had itso good, or so easy. Because now there’s our Interactive Business Management System (IBMS) . .. which lets your micro-computer perform’like a larger unit, so you can mind, monitor and manage every aspect of your business accounting A Full System While it’s extremely easy to use, IBMS jis a full system to handle the full job. The ten program modules can generate everything from the original invoice to the final profit/loss statements, plus many peripheral operations. The special Menu includes: System Start-up. Accounts Re- ceivable. Accounts Payable. Perpetual Inventory. Payroll. Fixed Assets. General Ledger. Plus Mailing Labels, and an Appointments Calendar. Save Maximum Time Since IBMS is a totally interactive system, multiple- entering of data is eliminated. Make an entry in one area and it automatically updates all con- cerned areas! No duplication of effort, no wasted time, no problems. Proven. And then some. It took 3 years to develop IBMS, including shake- down and on-site testing. As a result, it’s reliable and versatile and its documentation is thorough and easily understandable. No wonder we con- sider it 5 years ahead of anything else available to the Apple Il user. Introductory Offer The complete IBMS software package, on mini- floppy disks, documentation, and the backing of Programma International, Inc. is offered for a limited time at the Introductory Price of $1495.00. You'll be amazed how it can satisfy you by saving you time, effort, money and employee growth. The Key toBusiness Management Pues L : Kg PROGRAMMA PROGRAMMA INTERNATIONAL, INC. 2908 N. Naomi Street, Burbank, Ca 91504 (213) 954-0240 * Apple is a trademark of Apple Computer, Inc. PAGE 32 dots, with the least significant bit (bit 0) controlling the left-most dot of the group. In the vertical direction, things are not organized in an or- derly fashion. Each box represents 8 bytes in memory, with each byte corresponding to a different vertical position on the screen, and the bits within the bytes controlling the 7 horizontal dots as explained above. Now let's see if | can straighten all this out with an example. Suppose we want to know the address of the byte that controls the 87th dot from the left on the 23rd line from the top of the screen. Twenty-three divided by 8 is 2, with a remainder of 7, so we go down to the third ver- tical box from the top, which has an address of 8448 (decimal), and we want the 7th line in that box, which means we add 6144 to 8448. (We go to the third box, because box 1 controls lines 1-8, box 2 lines 9-16, etc., and we use the diagram in the lower right hand corner to find the number 6144 to be added to the base address.) Then we move over to the right to add in the contribu- tion of the horizontal position. Eighty-seven divided by 7 is 12 with a remainder of 3. So we go over to the 13th box (which is labelled 12 because the numbering starts with * 3 x 4 x 3 x & x z x 8 x q x ° x il x 12 x 13 x x 15 x 16 x 1 OT 2 Rh, 19 HBASH 20 xO 3 YO LFMG 23° HPAG ie 26 FURS 27 SETLFT 28 PRNT 4 FEED WAIT 31 x 32 * BY WASHINGTON APPLE FI Printer mus with correc inverse moder lef