Text content (OCR)
Open-Apple
Releasing the power to everyone.
May 1987
Vol. 3, No. 4
ISSN 0885-4017
newstand price: $2.00
photocopy charge per page: $0.15
Verses added to a golden oldie
At the very core of every Apple II ever built, from the first Integer Basic
model to the Ilgs, you'll find something called the System Monitor. This built-
in software allows you to examine and contro! the Apple II at a very intimate
level. Citizens of other computer kingdoms, who don’t have similar
programs built into their computers, will tell you the Apple Monitor has little
significance — they'll say only assembly language high priests can use it. In
fact, just the opposite is true.
The significant thing about the Apple Monitor is that it has lured tens of
thousands of mere mortals into learning how the Apple II works. There are no
secrets in our kingdom (it's a tradition handed down from Woz) and there are
no high priests. The Monitor is one of the major tools used by laypeople to
learn how to release the power of the Apple II. Likewise, it is this body of
thousands of laypeople who have learned how to release the Apple II's power
that make the Apple II different from the machines at the center of other
kingdoms.
Being one of the mere mortals myself (computer high priests rarely accept
English majors as one of their own), I've always had a great deal of respect for
the Monitor. Way back at the beginning of Open-Apple’s Volume 1 you'll find
two articles, “A Song Called the System Monitor’ (February 1985, pages 19-
112) and “A Song Continued” (March 1985, pages 120-121), that were
written to introduce the Monitor to those of you who had never used it. The
articles describe the Monitor as it exists on the original Apple II, the II-Plus,
the Ile, the Ic, and the enhanced Ile.
This month we're going to summarize what was explained in detail in
those issues and we're going to take a closer look at the Monitor as it exists
on the new Apple IIgs. The Monitor changed hardly at all between the original
Apple Il and the enhanced Ile, even though the machines themselves
progressed through several revisions. For example, the memory capacity of
the machines grew from 48K to 64K to 128K, but the memory-examining
capacity of the Monitor never grew beyond the original 48K.
Apple has fixed all this in the IIgs, however. The Ilgs Monitor has been
enhanced with new powers and new commands. On the IIgs you can
examine and manipulate memory in the “language cards” and in the
“auxiliary bank” as easily as any other memory. In addition, you'll find
memory displays that can take advantage of 80-column screens and show
ASCII values, commands for converting numbers back and forth between
hex and decimal, and several commands that support new features of the
IIgs.
Entering the Monitor. The usual way of entering the Monitor is from
Applesoft with a CALL -151 command. The entry point of the machine
language program that is the Monitor starts at $FF69, which is equivalent to
-151 in decimal (or 65385, take your pick).
Another way to get into the Monitor is to get the microprocessor to execute
a BRK (break) command. The microprocessor will do this whenever it
encounters a zero (the machine code for BRK) as it is executing a machine
language program. Most users think of this as “crashing into the Monitor.”
When the program you are using beeps, puts an asterisk on the screen, and
displays a new row of letters and numbers every time you press return, this is
what has happened to you. Unless you have a Ilgs, you'll see a line that looks
something like this somewhere on your screen:
0802-A+08 X=15 ¥=25 P=30 S=E4
Ona llgs, the line looks more like this:
00/0800: 20 00 BRK 00
A-0008 X=0015 ¥=0025 5-014 0=0000 P=30 8:00 K=00 M=0C Q=80 L=1 a= x=1 e=1
Machine language programmers use BRK for debugging purposes. A BRK
stops a program at a spot selected by the programmer and allows
examination of the microprocessor's memory registers and the computer's
memory. When a commercial program executes a BRK and crashes into the
Monitor, it's a bug, Finished programs aren't supposed to do that.
A third way to get into the Monitor, but only on the llgs, is with a desk
accessory called Diversi-Hack. Interrupt any program with open-apple/
control/escape to get to the Ilgs desk accessory menu, choose Diversi-Hack
from themenu, and you are in the Monitor. The IIgs Monitor's new Q(uit)
command will take you back to the desk accessory menu; a quit from there
will take you back to the program in progress. For more about Diversi-Hack,
see my introduction to this month's letters.
Once you get into the Monitor, you'll find that its commands fall into four
groups. There are commands for examining memory, commands for
changing memory, commands for program control, and miscellaneous
commands.
Examining Memory. The values found in a computer's memory cells can
represent just about anything, but most often they represent either numbers,
ASCII characters, or machine language programs. The IIgs Monitor gives you
tools to examine RAM and ROM memory from each of these three perspectives.
(The Monitor on older Apples doesn’t include an ASCII display, but Open-
Apple already solved that problem back on page 112. Ifyou don’t know RAM
from ROM from registers, go back to the beginning of our second volume and
try “The Magic of Peek and Poke,’ February 1986, pages 2.2-2.5.)
To look at memory from the perspective of numbers, you enter the hex
address that you want to see the contents of and press retum. Successive
retums display successive bytes of memory. To display a range of memory all
at once, enter the beginning and ending addresses separated by a period.
The llgs offers several enhancements to this system. First of all, the IIgs
displays the ASCII representation of each byte along with the numerical
“WHY WORK FOR APPLE? THINK BIG SON.
YOU CAN SIMULTANEQUELY BRING 10,000
USERS TO THEIR KNEES WITH A SYSTEM
LIKE THIS ONE”
3.26 Open-Apple
value. Ifyou are in 80-column mode, the Monitor will notice it and will display
16 bytes on each line instead of the usual eight. Finally, pressing control-X will
terminate the display of a range of memory values. On older Apples, the only
way to terminate a range display is to press control-reset. Here is what the 80-
column memory display looks like on the IIgs:
¥2000..20FF
00/2000:00 01 2 83 04 05 06 07 08 09 OA OB AC 00 OE OF-
00/2010:10 11 12 13 14 15 16 17 18 19 18 18 1C 10 1E 1F- :
00/2e20:28 21 22 23 24 25 26 27 28 29 2A 2B 2C 20 2E aF- !nssa’()#+,-./
00/2030:30 31 32 33 34 35 36 37 36 39 3A 38 3C 30 3 3F-0129456789:;<=>7
00/2040:40 41 42 43 44 45 46 47 48 49 48 48 4C 40 4E 4F-BABCOEFGHIJKLMND
90/2050:50 51 52 53 54 55 SG 57 SB S9 SA SB SC SO SE SF-PQRSTUVHXYZ[\]"_
00/2060:60 61 62 63 64 GS 66 67 6B 69 GA 6B GC GD GE GF-“abcdefghi jkImno
00/2070:70 71 72 73 74 75 76 77 78 79 7A 78 7C 70 7E 7F-parstuvuxyz{| }~.
00/2080:80 61 82 63 64 85 86 87 88 G9 GA GB EC ED BE GF- .
00/2090:90 91 92 93 94 95 96 97 98 99 9A 9B 9C 90 9E 9F- :
00/20R0:R@ AL A2 AB AA AS AG A7 AB AS AA AB AC AD AE AF- !NSxR"()#+,-./
0/2080:80 81 82 83 84 85 86 B7 6B 69 BA BB BC BO BE BF-0123456789:;<->?
@0/20ce:ce C1 C2 C3 C4 CS C6 C7 CB C9 CA CB CC CO CE CF-8ABCOEFGHIJKLHNO
@0/2000:08 01 02 03 D4 DS D6 D7 0B 09 0A 0B OC OD DE OF-PGRSTUVUXYZ|\) "_
00/2060:E0 £1 E2 £3 £4 €5 £6 £7 EB £9 EA EB EC ED EE EF-"abcdefghi jklano
00/20F@:Fa Fl F2 F3 F4 FS FG F? FE F9 FA FB FC FD FE FF-pqrstuvuxyz{| }~.
The ASCII characters on the right side of the display represent the same
sixteen characters that appear numerically in the midsection of the display.
This example shows a range of memory that | purposefully filled with values
from 0 to 255 so you could see the relationship between values and ASCII
characters. Control-characters are displayed as periods. No distinction is
made between high-value and low-value ASCII.
The numbers on the left edge represent the memory address of the first of
the sixteen bytes in each line. The 6502 microprocessor used on earlier
Apples could accommodate only 65,536 discreet memory cells. Thus
Monitor addresses on these Apples ran from $0000 to $FFFF. The micropro-
cessor in the IIgs, on the other hand, can accommodate 16,777,215 discreet
memory cells. These are arranged as 256 “banks” of 65,536 cells each. The
number in front of the slash indicates which bank you are looking at. The
number after the slash gives the address within that bank.
To look ata different bank, you can enter a number such as 02/2000.20FF.
This would display “page” $20 in bank $02. The addresses you give must
both be within the same bank.
L(ist). The third perspective for looking at memory is with the L{ist)
command. Enter an address and “L” and you will see a “disassembly” of the
section of memory that follows that address. Not all ranges of memory
actually hold machine language programs. Some hold data, some hold
programs in other languages, some hold nothing at all. The big limitation of
the list command (a limitation it shares with other disassemblers) is that it
can'ttell real machine language code from other kinds of data. It “disassem-
bles” everything, whether the results are meaningful or not.
The ligs list command is able to disassemble all the 65816 operation
codes and addressing modes. For a complete description of these codes
and modes see "A 65802/65816 pre-boot” and “Introduction to the 65802/
65816" in our August 1986 issue, pages 2.49-56.
One big problem that occurs when a program tries to disassemble 65816
machine code is that the “immediate mode” of three commonly-used
instructions, LDA, LDX, and LDY, can be either two or three bytes long and the
disassembler can’t tell which. These commands load the microprocessor's
A,X, or Y register. With immediate addressing, the data that is to be put into
the register is embedded within the program immediately after the
instruction byte. If the registers are set up for 8-bit data, these instructions
are two bytes long (one instruction or operation-code byte and one data
byte). If the registers are set up for 16-bit data, on the other hand, these
instructions are three bytes long (two data bytes). But a disassembler can’t
tell which is which. For example, get into the IIgs Monitor and try this:
#FF [0203
dsm =x 1SLCBANK (2/1)
FF/0203: 9 00 Loa 100
BRK A2
FF/0207: 00 05 BRK 05
Those BRK instructions in the second and third lines don’t look quite right.
Perhaps this section of code was written to be executed with 16-bit registers.
To tell the disassembler that you’d like to see the code listed that way, enter
O=m (16-bit A register) and 0=x (same for X and Y registers). Note that the
format of these commands is backwards from what Applesoft programmers.
Vol. 3, No. 4
would expect (0=m, not m=0), that “m” and “x” must be entered in lower
case, and that the current list status of "m” and “x” is always displayed at the
top ofa listing. For example:
2O=n O=x 0203.
@=n @=x — 1=LOBANK (0/1)
FF/0203: 99 00 08 LOA Hooee
FF/0206: 92 00 @@ LOX HoSee
When you examine memory with the Monitor and you look at bank zero,
you will always see the “language card” RAM in the address space from
$D000 to $FFFF. If what you really want to see is the ROM that is normally
found in this address space, look for it in bank $FF. That's what we've done
here. (There’s more ROM in bank $FE.) Note in the above examples that once
you've set the bank to $FF (or whatever), it will stay there (with one exception
to be noted later) until you change it again.
Unlike the ROM code, the hardware softswitches and peripheral card
firmware that appear in the address range from $C000 to $CFFF on earlier
Apples appear there still on the Ilgs (but in banks $00, $01, $E0 and $E1
only). Thus, two banks of $D000-$DFFF memory are needed to squeeze 64K
of RAM into these banks. To control which bank you are looking at, enter 1=L
to see the main bank (usually called bank 2 in the Apple literature) and O=L_
to see the secondary bank (usually called bank 1).
In addition to allowing you to examine sequential memory bytes as values,
ASCII characters, and assembly language mnemonics, the llgs Monitor gives
you the power to examine memory by searching for a specific byte pattern
and by comparing two segments of memory for differences.
P(attern search). The first Apple II Monitor to have a search command
was the one in the enhanced Ile. On that machine you can search memory for
any one-byte or two-byte value. The command's syntax is “YYXX<adr.adrS”
where YYXX is two sequential bytes appearing as XX YY. Yes, they're
backwards.
The Ilgs search command is very different from the one in the enhanced
Ile. First ofall, rather than being known as S(earch), as on the enhanced lle, it
goes by P(attern search), Second, the values (or pattern) you are searching
forcan be up to 236 bytes long, Third, the pattern you are looking for must be
surrounded by backslashes. Fourth, the pattern can include hexadecimal
values, ASCII values, or “flipped” ASCII (flipped means backwards—"“BOB”
instead of “BOB,” for example). Try this:
¥\20 ED FO\<FF/F8Q0.FFFFp search Monitor code for JSR $FOED
FF/F9¢C:
FF/FDaA:
FF/FOG4:
FF /FO6C:
FFIFFQF:
FFIFF34:
FFIFF37:
#\"Apple”\<FF/@000.FFFFp search bank SFF for “Apple”
FF /e802:
FF /8987:
FFIC767:
FF/F914:
FF/FB09:
When you search for ASCII characters as we did above, the search finds
only high-value ASCII characters. However, the IIgs Monitor has an “ASCII
filter mask” that will modify the characters you specify to low-value ASCII or
to other weird stuff. The filter mask goes by the name “F’ It can be set to
anything from $00 to $FF with the =F command. $FF is its natural setting. $7F
will getyou low-value ASCII. The other 254 settings are of questionable value.
Ty this:
*7F SF
*\"Apple”\<FF/@000.FFFFp search bank $FF for “Apple”
FF/2n19:
FF/9128:
*\POGO’ \<8000.6FFFp search @0/8000 to BFFF for “OG0P~
00/8893:
Notice a couple of things here. The search for “Apple” with the filter set to
$7F turned up two more occurrences that the first search didn’t catch.
Likewise, none of the first search's hits turned up in the second search. This
means the “ASCII filter mask” doesn’t create “wildcard” bits. Instead, it
May 1987
simply clears bits in the character pattern specified. Only exact matches with
the new pattern will be found. Secondly, notice that in the search for POGO
backwards (the backwards part is specified by means ofa single quote mark
rather than a double quote mark) we didn’t specify a bank address, but in all
the other searches we did. This is because the IIgs search command always
defaults to bank zero unless you specify another bank. This is inconsistent
with the other Monitor commands, which default to the last bank specified,
and is the exception to the last-bank-specified default that was mentioned
earlier. This is probably a bug, but maybe there's a good reason for it | haven't
discovered yet.
V(erify). The command for comparing, or ‘verifying’ two segments of
memory hasn‘t changed from earlier Apple Ils, except that bank addresses
can now be specified. If “adr” means an address of either the form "XXXX" or
“XX/XXXX”" then the format of this command is “adr‘adr.adrV’. The two
segments of memory you are comparing can be in different banks, but
neither segment can cross a bank.
For example, load an image of Applesoft as found on the IIc into a Ilgs at
$2000. (More on how to actually do this later.) To compare this image to
what's in the IIgs, do this:
¥00/2000<FF /0000.F7FFy
FF/E006:00 (36)
FF/FAFE:30 (50)
FF/F233:03 (09)
FF/F234:F8 (F2)
FF/F3CB:20 (AD)
FF/F3CC:3A (73)
FF/F3C0:F9 (CO)
As you can see from the display, the two images are almost exactly the
same. For a complete description of the differences between IIc Applesoft
and earlier versions, see “Up where Applesoft lives” in our June 1985 issue,
pages 140-44. The primary difference is that IIc Applesoft (and now
Applesoft on the IIgs) includes support for double-low-resolution graphics
(80 pixels across the screen by 48 high).
(The differences between llc Applesoft and IIgs Applesoft are as follows:
$E006 is a spare byte that has had various values in various versions of
Applesoft—the zero in this byte on the IIgs matches what the original
Applesoft had. The next three changes fix a bug in the double-low mode that
allowed the Y coordinate to be as large as 80 on PLOT and SCRN commands,
when 48 should have been the maximum. The last three changes were
necessary because the softswitch for reading whether double-resolution
graphics are turned on isn’t in the same place on the IIc and Ilgs.
Mysteriously, a one-byte change necessary to fix a bug in the double-low
SCRN function, which was mentioned in our June 1985 article, wasn’t done.)
Modifying Memory. There are several ways you can use the Monitor in all
models of Apple II to modify RAM memory. To change one byte, enter the
address of the byte you want to change, a colon, and the newvalue. To change
the bytes that follow the first, enter more values, but be sure to include a
space between each. After you press return you can continue where you left
off by simply entering a colon and more values.
In addition to entering hexadecimal numbers, the IIc, enhanced Ile, and
IIgs have what's called an “ASCII input mode.’ On the Ic and enhanced Ile
you can store the ASCII code for a letter in memory by typing the letter with a
single quote in front of it. Ifyou want to enter several letters in a row, you must
precede each with a single quote, like this:
42000:'D “r ‘ag ‘on’ ‘s
32000.2007
2000- C4 F2 EL E7 EF EE AP FS
Iic/enhanced Ile ASCII input mode
ASCII input mode on the Ilgs is much different. Instead of preceding each
letter with a single quote, you surround the letters with double quotes. The
characters you enter are marched through the ASCII filter mask (mentioned
earlier in the discussion of the search command) before being stored in
memory—thus you can use the filter to obtain low-value ASCII. Only high-
value ASCII is available on the IIc and enhanced Ile. Here are some
examples:
¥07/100: “Dragon's”
*100.10F
@7/e100:C4 F2 EL £7 EF EE A? F3 FF FF FF FF FF FF FF FF-Dragon’s........
110: “Dragon“s*
*110.11F
07/0110:F3 A2 EE EF FF FF FF FF FF FF FF FF FF FF FF FF-S*n0...seeeeeee
Open-Apple 3.27
FFF
¥120: "Dragon's.
¥120.12F
07/0120:44 72 61 67 GF GE 27 73 FF FF FF FF FF FF FF FF-Oragon’s...-....
As you can see in the second example, a single quote is supposed to give
you backward, or flipped, ASCII. However, it seems to work only with the last
four characters you enter. That's a bug. In the third example, I changed the
filter mask to get low-value ASCII. Notice that you don’t really needa closing
quotation mark if you're at the end of a line. (In comparing the IIgs with the
lle and IIc | just noticed another important Monitor difference —on the IIgs
the keyboard's delete key works, at last, at last.)
M(ove). The move command, which is available on all versions of the
Monitor, provides another way to modify memory. The command syntax is
“destcadr.adrM” where “dest” is the destination address and the “adr.adr”
range defines the segment of memory you want to move. On the Ilgs this
command can move memory from bank to bank, but just as with the verify
command, it can’t deal with ranges that cross a bank boundary. It's also
important to make sure the destination area isn’t inside the source area, or
you may get results other than those you expected.
Earlier | mentioned that I'd show you how to get an image of IIc Applesoft
into the IIgs, so that the two can be compared. You can't just BSAVE
IIC.FPIMAGE.A$D000,L$2800 because while the BSAVE is going on ProDOS
will be active. The snapshot you'll get will be of the ProDOS kernal rather than
of Applesoft. This can be bewildering, The solution is to either take the
snapshot with DOS 3.3, or do this:
*200060000.F7FFm
#3006
JBSAVE TIC.FP, IMAGE ,AS2000,L$2600
move Applesoft’s image to $2000 (do this on a IIc)
Z(ap). The IIgs has a new command for filling a range of memory with a
specific value. The syntax is “valkadr.adrZ”, where val is a hex number. For
example, 7<07/0000.FFFFz will put a seven in every byte in bank seven, which
is not necessarily a good thing to do. You can also zap memory on older
Monitors, but it requires a trick. Try:
#2000:0
#2001<2000.20FEM
Because the destination address is inside the source address, the effect of
this command will be to move the value at byte $2000 into every byte on that
page.
The Mini-Assembler. The final way to modify memory with the Monitor is
to use the Mini-Assembler. The heritage of the Mini-Assembler goes back to
the original Apple II, where it could be found as part of Integer Basic. You can
run the Integer Basic Mini-Assembler by entering the Monitor while Integer
Basic is active and typing "F666G”. Because it uses “undocumented entry
points,’ however, the Integer Basic Mini-Assembler doesn’t work right on the
IIc or IIgs. On the enhanced Apple Ile, the 3.5 ROM Ilc, and the IIgs, you can
start up newer versions of the Mini-Assembler directly from the Monitor, with
or without Integer Basic, by entering an exclamation point.
The Mini-Assembler can be used to write short, uncomplicated assembly
language programs. It's much easier to write longer programs on full-blown
assemblers because they allow you to give names or “labels” to program
segments and addresses, because they make it easy to insert new lines in
what you've already written, and because they provide many other amenities
that the Mini-Assembler doesn't. All the Mini-Assembler can dois allowyou to
type in one assembly language mnemonic and operand at atime; it converts
these into the equivalent machine language values and stores them in
memory. Nonetheless, it's a useful and handy tool to have around.
It was possible to execute Monitor commands from within the original
Mini-Assembler by starting a line with a dollar sign. This isn’t possible with
the Mini-Assemblers that start up with an exclamation point. However, it's not
necessary either because you can switch between the Mini-Assembler and
the Monitor so easily on these machines (the exclamation point gets you in,
retum ona blank line gets you out). In addition, the Iigs Mini-Assembler does
allow you to directly enter hex or ASCII values into memory.
Once you are in the Mini-Assembler, the first thing you must do is provide
the address where you want your machine code to be placed. Follow that with
acolon and an assembly language instruction. The allowable instructions,
addressing modes, and addressing mode formats for the Mini-Assembler are
shown in our August 1986 issue, page 2.52. The llgs Mini-Assembler can
handle all of the 65816 instructions and addressing modes; the 3.5 IIc model
can handle all 65C02 instructions; other models handle only the 6502
instructions and modes.
3.28 Open-Apple
Begin each line you enter after the first with a blank space ifyou want that
line’s machine code to follow the previous line's. On the Ilgs, a colon instead
of a blank space tells the Mini-Assembler that hex data follows. A double
quote mark instead of a blank indicates ASCII characters (which will be
forced through the ASCII filter mentioned earlier). A number indicates you
are giving a new address for storing machine code. Thus:
*
12000:LOX HO
00/2000: A2 00 LOx #09 load a zero into X register
"LOA 200E.x
0/2002: 8 OE 20 LDA 200E,x load A with uhat’s at $200E+x
1 BEQ 2000
ee/200s: Fo 06 BQ 2000 {+06} branch on equal--did A get a zero?
JSR FOED
00/2007: 20 ED FD JSR FED Jump to the PRINT subroutine at SFDED
"INK
00/2008: EB INK increment X (X=X+1)
BNE 2002
0/2008: 00 FS BNE 2002 {-08} if xX >8, branch to get next character
1 RTS
00/2000: 60 RTS return to caller
‘Read Open-Apple every month for health and wealth.
1:0
How did I know while I was entering the second line that the ASCII string
the routine prints would occur at $200E? I didn’t. This is the kind of thing a
true assembler handles easily. In this case, it's necessary to guess at the
correct address (in order to save space for the instruction), then go back and
correct it after you have finished the program and know the correct address.
Itsalso necessary to guess at and correct the destination of the branch in the
third line of the program. Incidentally, the Mini-Assembler display you see on
your screen is much cleaner than what's possible to show here — the output
for each line overwrites the input. Try it and see.
Program control. Once you've entered the above program with the Mini-
Assembler, press return on a blank line to get back inside the Monitor and try
this:
*2000g
Read Open-Apple every aonth for health and wealth.
The G(o) command tells the Monitor to execute the subroutine at the
address you give. $2000 is the temporary home of the Chinese fortune
subroutine we just entered with the Mini-Assembler.
An important, but often overlooked, aspect of the (G)o commang is that it
loads the microprocessor’ registers with specific values, which you can
control, just before jumping to the subroutine at the address you specify.
(Incidentally, it does JSR, not JMP, so if the routine you call ends with an RTS
you'll return cleanly to the Monitor, as in the example here.)
Ty this:
¥(press control-E and return)
---display on II, Il-Plus, Ile, IIc, enhanced Ile
A=08 X=15 Y=25 P=30 S=FO
display on 3.5 IIc
N=00 A208 X=15 Y=25 P=30 S-FO
=+-display on IIgs
0008 X=0015 ¥=0025 S-01F0 00000 P=30 B00 K-00 M=0C J=80 L=1 m=1 x-1 e=1
Control-E displays the values that will be placed in the microprocessor's
registers when control is passed to the address you specify with the G(o)
command. On the 3.5 IIc and the IIgs some of the displayed values aren't
actually registers, but are “flags” that indicate which memory banks will be
active when G(o) is executed, as well as other stuff. You see this same display
after the microprocessor hits a BRK instruction, as mentioned many
paragraphs ago. Not only is the display the same, so are the values. In other
words, a BRK puts you into the Monitor and displays the values in the
registers when the BRK occurred. The flags indicate the status of the machine
at that time. G(o) returns to the program with those same values in the
registers and that same machine status.
You can, however, change the values from the Monitor if you like, so that
G(o) will use different values or flags. On all machines except the IIgs you do
this by pressing control-E and return to get the register display. Then enter a
Vol. 3, No. 4
colon at the beginning of the next line followed by the value you wantin the A
register, the value you want in the X register, and so on. If you'd like to
experiment with this, be aware that changing the P or S register to a random
number sometimes locks the machine up so tight you need a can opener to.
get it back open. (To change the M register on the 3.5 IIc use “44:val”.)
On the Iigs, on the other hand, you change the values that will be placed in
the registers by entering the new value you want, an equal sign, and a letter
designating the register you want to change. We used this format earlier in
our discussions of the L{ist) command and the ASCII filter. On the IIgs you
can also restore the registers and flags to a “normal” configuration by
pressing control-R.
The program we entered earlier with the Mini-Assembler begins by loading
the X register with a zero. You can see what would happen with other values by
changing the X register value with the Monitor and G(o)ing to $2002. For
example:
-srall but IIgs ++-Tlgs
*(control-£ return)
(registers are displayed)
#200 05
*20026
*(control-£ return is optional on IIgs)
(registers are displayed)
152x
20026
Open-Apple every month for health and wealth.
The A register is the microprocessor’s accumulator, where all math
operations are done. X and Y are the index registers. S is the stack register,
which points a crooked finger at the current stack position. P is the
microprocessor's status register. The meaning of its bits change slightly,
depending on whether the microprocessor is in 6502 (“emulation”) mode or
65816 (“native”) mode. Only the IIgs has these two modes. The “e” flag tells
you which mode the machine is in; 1=6502 mode, 0=65816 mode. Here's
what the bits in the P register mean:
Neaning of the P(rocessor status) register
NviBoIze
NvMxOTZe
esl on Ilgs (6802 mode) and all other Apple IIs
20 on Ilgs (65816 mode) only
N Is sign; 1snegative
V Is overflow; 1=true
1 is unused
Wt is A-register width; 1-8 bits, O=16 bits
B is break flag; 1-8RK, O>harduare interrupt
X 1s X-register width; 1-8 bits, 0-16 bits
D Is binary coded decimal Flag;
I As interrupt flag; 1=interrupts disabled
Z is zero flag;
C is carry fla
The bits of the M register indicate the state of the machine's memory banks
when a BRK occurred, or how you want the banks arranged for the next G(o)
command. Both the 3.5 IIc and the IIgs display an M register. Here's what the
bits mean.
true
Meaning of the M(enory status) register
0 P2 RD WR LC Bl 82 00
AZ PX RD WR LX BX AR CX
3.5 He only
IIgs only
@0 is unused
AZ is alternate language card/zero-page/stack; 1=active
P2 is STOREGO/PAGEZ status; 1=both active
PX is PAGE2 status only; 1-active
RD Is auxnen read status;
WR is auxnen urite status; I=active
UC is language card read status; Iscard active
LX As language card status; 1=RON active
B1 is language card bank 1 read status; Iactive
BX is overridden by L (see text); Isbank 2,
82 is language card bank 2 read status
PR is alternate ROM bank (see text); l=active
@0 is unused
CX is alternate SC100-SCFFF RON;
zactive
The meaning of the bits in the 3.5 Ics M register is similar to, but not
exactly the same as, the M register on the Iigs. In particular, the LC/LX bits,
which indicate whether ROM or RAM is active in the $D000-SFFFF memory
area, have exactly opposite meanings. On the Ica one in that bit means RAM
is active, on the igs a one means ROM is active. The IIc uses two bits to
indicate which language card bank is being used; if neither (if ROM is active),
both bits are cleared to zero. The IIgs uses just one bit for this (1=bank 2,
O=bank 1), but changing that bit in the M register is a useless exercise—it's
May 1987
always overridden by the L flag, which we looked at earlier in our discussion
of the L{ist) command,
Both the 3.5 [lc and the IIgs have an alternate 16K ROM bank that can be
tumed on with softswitches. Only the llgs has a bit in the M register to activate
that ROM, however. On the Ilgs a program can obtain all of the information in
the Monitor's M register, in exactly the same format, by reading byte $C068.
Not only that, but by writing to the same byte (which is called the “state”
register), a llgs program can change the machine's memory configuration,
This provides Apple's programmers with a speedy way to save and restore the
memory configuration of the IIgs during an interrupt.
The control-R(estore registers) command in the IIgs Monitor sets the M
register to $08. A G(o) with M=08 would tum on the lower 48K ofthe main 64K
bank of RAM and put the Applesoft/Monitor ROM in the $D000-SFFFF area.
The Q register (for “quagmire,” according to the IIgs documentation) that
appears in the IIgs memory display combines information from two other
Iigs hardware registers. These are the “shadow’ register at $CO35 and the
“configuration” register at $C036.
On the IIgs, what you see on your screen is always a reflection of
information stored in RAM memory banks $E0 and $E1. (On other Apples the
active video area is in banks $00 and $01) Since Apple II programs written
before the Ilgs appeared don’t know bank $E1 from Capitol Federal Savings
and Loan, the IIgs hardware automatically “shadows” anything that is written
into certain parts of banks $00 and $01 into the same parts of banks $E0 and
$E1 It’s as if you were able to deposit a dollar into First National and have
your sugar daddy make a matching deposit into E-First National for you.
There may be situations, however, when you wouldn't want a matching
deposit made. For example, if your program is using the high-resolution
graphics page 1 memory area ($2000-$3FFF) for data instead of pictures,
there may be no reason to have the data shadowed into E0/2000-3FFF as
well. With shadowing on, anything previously stored in the $2000-3FFF area
of bank $E0 would be destroyed by writes to 00/2000-3FFF. Shadowing also
slows down the llgs slightly. Under ProDOS 16, shadowing is normally turned
offand video display manipulations are made directly to banks $E0 and $E1.
Under ProDOS 8, DOS 3.3, and Pascal, shadowing is normally turned on.
Most of the bits in Q come from the shadow register. Only one, the one that
indicates machine speed, comes from the configuration register. Here's the
meaning of the bits in the quagmire register:
Meaning of the Q(uagaire) register
SP LM 00 AK SH H2 HL TL
SP 1s processor speed; 1=high, O-nornal
LM is Linear memory; 1=no 1/0 space at $C00@ in banks $00 and $@1
@0 is unused, must be zero
AX is auxnen hi-res override; 1=no hi-res auxnen shadowing
SH is super hi-res (£1/2000-SFFF); 1=no shadowing
H2 is main/aux hi-res page 2; Leno shadouing
HL is sain/aux hi-res page 1; Lsno shadowing
Ti is main/aux text page 1; 1=no shadowing
ControL-R sets the Q register to either $00 or $80. The speed is left as it was
before the control-R.
Notice that it is possible, by manipulating the LM bit on the Ilgs, to disable
the language cards and the $CO00-CFFF hardware in banks $00 and $01 If
you did this, the RAM in banks $00 and $01 would become continuous — the
primary language card bank (bank 2) would appear in the $C000 area and
the secondary bank would be at $D000. The $C000 hardware would appear
only in banks $E0 and $E1 However, this isn’t a practical alternative because
Ilgs interrupts use some machine language code that lives in the $CO00-
CFFF ROM in bank zero. Interrupts cease to work when you invoke the linear
memory option.
The other three registers shown in the IIgs register display are the direct
register (D), the data bank register (B), and the program bank register (K). For
more information on these registers, which are active only when the
microprocessor operates in 65816 mode, see the August 1986 Open-Apple.
X(ecute), R(esume), S(tep), and T(race). On the llgs, the G(o)
command can only be used to execute a routine in bank $00. If the routine
you want to start lies elsewhere, use the X(ecute) command. This command
expects the routine to end with an RTL (return from subroutine, long),
however. Like X(ecute), Resume) will also start up code in any bank. However,
it MLs (jumps long) rather than JSLing (jump to subroutine, long). Use it to
continue program execution after a BRK. G(o) and X(ecute) don’t work well
after a BRK—they mess up the stack with their own JSR/JSL.
‘S(tep) and T(race) are available only in the original Apple II Monitor and in
the 3.5 IIc Monitor. (Hooks were left in the IIgs for implementing these
Open-Apple 3.29
commands — they print “Step” and “Trace” on your screen at the moment)
S(tep) lets you execute machine language programs one instruction at a
time. As each instruction is executed, it and the contents of the registers are
displayed on the screen. 2000S, for example, would begin stepping through
a program living at byte $2000. To execute the next instruction, simply press
Sand return.
‘T(race) is similar to S(tep) except that it doesn’t stop after each instruction.
To exit T(race) on the 3.5 llc, press solid-apple. To slow it down to one step
per second, press and hold down on open-apple. Neither S(tep) nor T(race)
works with programs that use the same zero page locations as the Monitor
itself.
Miscellaneous Monitor commands. There are a large number of
miscellaneous Monitor commands that | should zip through for you. Some
of them, such as I(nverse), N(ormal), val+val, and val-val, have been around
since the original Apple II and are still available on the llgs. Others, such as
W(rite) to and R(ead) from cassette tape, have mercifully disappeared on
newer machines.
In the same class with I(nverse) and N(ormal) is the control-Y user
command. The control-Y command and the use of N as a command
separator (much as the colon in used in Applesoft) were discussed at length
in the February and March 1985 Open-Apples. Until the Ilgs, the + and -
Monitor commands were of little value because only one-byte answers were
displayed. The IIgs, on the other hand, can take four-byte operands and
display four-byte answers. The IIgs also has a multiply instruction (val’val)
that displays eight-byte answers. As before, all of these work with hexadecimal
numbers only (where 8+8=10).
While the DOS commands IN# and PR# are the correct way to turn on input
devices and printers, even from within the Monitor, the older Monitor
commands control-K(eyboard) and control-P(rinter) have been retained. (For
some reason, Basic.system commands don't work as well from inside the
IIgs Monitor as they do on earlier Monitors.) Likewise, 3D0G (or Q(uit) on the
IIgs) usually works better for returning to Applesoft than control-C or control-
B, but those commands have been retained as well.
The rest of the miscellaneous commands are new to the Ilgs. There are two
commands for converting numbers from hex to decimal and back again. To
convert to decimal, enter the hex number followed bya equal sign. To convert
to hex, enter an equal sign followed by a hex number, like so:
MF
Decimal-> 255 {+255}
#2255
Hex -> $000000FF
Control-T changes the current screen display to text page 1 ifyousomehow
crash into the Monitor while viewing graphics page. Control-” (control-shift-
6) allows you to change the cursor character. Whatever character you enter
after control-" will become a flashing cursor. Try it. This also works in
Applesoft on the IIgs.
=Tis a IIgs Monitor command that was mentioned in last month's letters
section. It prints the current time on your screen. It has a related command,
=T=, which allows you to reset the IIgs clock. I recommend using the control
panel instead.
Finally, the IIgs has a “tool locator” command. This command can be used
to enter toolbox calls. It begins with a backslash, followed by a number that
indicates how may bytes worth of input are needed by the tool, followed by a
number that indicates how may bytes of output the tool will return, followed
by the input bytes, followed by the two-byte tool number, another backslash,
andaU.
Here are two examples of the U command that call the ReadTimeHex and
ReadASCliTime tools discussed last month (“Time to look in the toolbox,”
pages 3.21-22.):
x\0.80 3\U (mo inputs, 8 bytes of output, tool $2003)
Tool error-> 0000
00 00 16 57 OE 03 84 04
*\40 080200 F 3\U 2000.201F (4 in, none cut, $00002000, tool $0FO3)
Tool error-> 0000
20/2000:A0 84 AF 81 BS AF BB 87 AQ B1 80 BA BO 83 BA B2- 4/15/87
20/2010:A@ 00 CD 22 00 22 00 89 G2 22 00 G2 00 00 2 00-6 PI
This call always returns a “tool error,” however, ifthe error number is zero,
no error occurred.
That's the final verse in the new IIgs Monitor. It's becoming a very long song.
3.30
Open-Apple
Ask
(or tell)
Uncle
Ladies and gentlemen, start your pencils. On page
5.22 of last month’s newsletter, in the middle
the “AD” after the "00/030A:" should be an *
In regard to last month's letter “All chips not off
same block,” several subscribers have written in that
IIgs memory cards require a type of 256K RAM chip
called CAS before RAS. However, apparently not all
Iigs cards require this kind of chip. If you need chips
foraligs, |suggest you call or write Microprocessors
Unlimited (24000 S Peoria Ave, Beggs, OK 74421
918-267-4961). They sell bulk RAM chips at good
prices, provide fast service, send you excellent chip
installation instructions, and are keeping track of
what chips work in which ligs cards.
In my answer to last month's letter “Odd bank
out,” I asked for help on calling the igs memory
manager with the MiniAssembler. I've gotten some
good help on that one—you'll read all about it next
month. One of the people who responded was Bill
Basham of Diversi-DOS fame. Basham has already
developed three programs for the Ilgs that are the
most exciting llgs packages I've seen to date. Not
because of stunning graphics or sound, mind you,
but because of the way they use the memory
manager. Diversi-Cache ($35) speeds up Apple 3.5
drives (not UniDisks) by storing the tracks most
recently accessed in RAM. Diversi-Key ($45) is a
memory-resident keyboard macro program that
hides itself inside the Ilgs and provides macros for
all your programs. You have to see this one to
believe it. It has lots of bells and whistles, too. With
either of the above programs you also get Diversi-
Hack, the wonderful little desk accessory mentioned
in this month's lead article that lets you get into the
Monitor from the midst of anywhere. These programs
work only on the ligs, of course, and require 512K.
(Diversified Software Research, 34880 Bunker Hill,
Farmington, MI 48018-2728 313-553-9460).
Slot 3 RAMdisk rules
Why does Apple Writer 2.0 disconnect RAMdisks in
slot 3? Can this be changed? My RAMWorks card
would be useful as a RAMdisk if Apple Writer would
stop disconnecting it.
Jerry Hill
FPO Seattle, Wash.
You raise an extremely interesting question. Apple's
“ProDOS Technical Note #8” specifies an exact
protocol that programs are supposed to use to
determine whether a disk device in slot 3 should be
disconnected or not. This information is also included
in the Addison-Wesley edition of the ProDOS Tech-
nical Reference Manual (pages 90-91).
Programs that use both 64K banks of memory,
such as Apple Writer 2.0, have to disconnect the
ProDOS slot 3 RAMdisk because it also uses the
auxiliary 64K bank. If both were active at the same
time each would overwrite the other and chaos
would reign.
However, many other RAMdisks, such as the one
that came with your auxslot RAM card, either don’t
use the 64K extended memory area or can be
configured not to use it. Since these RAMdisks don’t
interfere with 128K programs, there is no reason
128K software should disconnect them. Tech Note
#8 has specified since late 1984 what RAMdisk
developers and what 128K program developers
need to do to avoid needless disconnection of slot 3
RAMdisks.
In the beginning, Apple's own software followed
the Tech Note #8 protocol—AppleWorks 1.2 follows
it exactly. But then something happened. Ken Kash-
marek, who recently sent me a ton of information on
this issue (much of which I'm using here), thinks that
the key event was Apple releasing its own memory
card. In order to keep Apple software from working
with third-party memory cards, Apple stopped fol-
lowing its own Tech Note, Kashmarek surmises.
According to the Tech Note #8 protocol, 128K
software is supposed to look through the ProDOS
global-page device list at $BF32-SBFSF and disconnect
only those devices that are connected to slot 3, drive
2 and that have the low two bits of their device
number set. This translates into units with device
numbers of $BF, $BB, $B7, and $B3. The key instruc-
tions that accomplish this feat load the device list
entries one-by-one, AND each with #$F3, CMP each
to #$B3, and branch to disconnect devices that come
up “equal.”
However, Apple Writer 2.0 and later, AppleWorks
L3 and later, and Instant Pascal have two bytes of
this protocol changed. All of these products AND
with #$70 and CMP with #830. This has the effect of
disconnecting any slot 3 disk device, whether
assigned as drive 1 or drive 2, whether RAMdisk,
hard disk, or Apple’s own disk.
There are two ways to fix the problem. One is to
search through programs that disconnect slot 3
RAMdisks looking for the byte string B9 32 BF 29 70
C9 30. Change the 70 back to F3 and the 30 back to
B3. This will make the program follow Apple's
published protocol and your RAMdisk will no longer
be disconnected.
Another way to avoid the problem is to not assign
disk devices to slot 3. Both Applied Engineering and
Checkmate Technology have updated their RAMdisk
software so that their RAMdisks can appear to be in
slot 2.
So, why do Apple Writer, AppleWorks, and Instant
Pascal disconnect third-party RAMdisks in slot 3?
Does a Fortune 500 company with $800 million in
the bank really disregard its own software protocols
just to give its RAM card a competitive edge over
those from third-party developers? I personally
believe the sincerity of Sculley, Yocam, and Gassee
when they say that they realize the importance of
third-party developers to Apple's success. However,
they can’t be expected to go over every byte of code
in Apple software. And it doesn’t take much imagina-
tion to picture some low-level product manager
being more concerned about achieving sales goals
than about Sculley's third-party philosophy.
Vol. 3, No. 4
Apple's officers need to let the public and its
employees know, by actions not words, where they
stand. Why doesn’t Apple's software follow Apple's
own protocols? Lots of people would like to know.
You wanna see a syntax error?
Is there any software that translates what you write
in American English to Mexican Spanish? Ifso, please
let me know, I need to constantly get memos, etc.,
translated.
Don Robinson
Coronado, CA
Dennis replies: The question you ask seems rea-
sonable; translation seems to be no more difficult
than looking up words in a dictionary and arranging
them into a sentence in the new language. In truth, it
isa lot more complex than that; there are verb forms,
context, and syntax (among other things) to consider
in making the translation. In fact, just translating
English into something a computer can understand
is difficult enough, to say nothing of then getting the
computer to express what it understood in Spanish.
Inorder to communicate with computers nowadays,
we humans have to leam languages such as Applesoft
or Pascal, which have very limited vocabularies and
very rigid sets of usage rules. In a word, our answer
to your question is “no,” at least for now, but the
issue as to whether such a program will ever be
available is interesting.
Translating human language falls into a realm of
computer research called artificial intelligence, or
“AL” Several excellent books have been written that
debate whether computers will ever be able to
handle such complicated tasks. One that argues
against the ability of a computer to simulate human
responses is Computer Power and Human Reason,
by Joseph Weizenbaum (W. H. Freeman). Weizenbaum
is a pioneer in Al research and was originator of the
computer game Eliza, which provides psychiatrist-
like responses to statements entered by a human at
the keyboard.
Another book, which argues against Weizenbaum’s
dismissal of the practicality of Al research, is Gédel,
Escher, Bach by Douglas Hofstadter (Vintage Books).
Hofstadter leads us through a difficult but enlightening
process of attempting to prove that a computer is
capable of at least simulating human intelligence.
Anyone seriously interested in natural language
processing or other Al topics may want to seek out
these books, as well as Artificial Intelligence, by
Patrick Henry Winston (Addison-Wesley), and follow
their bibliographies to further references.
The computer language of the Al community is
called LISP. A full Al version of LISP requires a lot of
computer power. LISP, by Patrick Henry Winston and
Berthold Klaus Paul Horn (Addison-Wesley), is a very
readable text about the subject. Logo, which at least
some of our readers (and more of their children) are
familiar with, was derived from LISP.
Natural language translation is similar in some
ways to the command interpretation done by adven-
ture games such as Zork. Zork’s interpreter was
originally implemented on a Digital Equipment Corp
minicomputer using a LISP-like language called
MDL, which was then “crunched down” to fit into
micros for the commercial versions of the game. For
some insight into the design of the interpreter, see
“How to Fit a Large Program Into a Small Machine,”
Creative Computing, July 1980, pages 80-87. For
additional articles on the design of adventure games
that seem to interact with their human players, see
May 1987
the rest of that issue of Creative Computing and the
December 1980 issue of Byte.
Readers who are interested in this kind of stuff
might like to investigate Polarware’s adventure-
game interpreter for the Apple II, which is called
Comprehend. The cost is $95 from Polarware, Box
SIL Geneva, IL 60134 800-323-0884.
CALL -875
| have a program that was written for my old II-Plus
and it worked fine—now I have a new IIgs and the
program sends me strange machine language screen
entries. The program includes both a CALL-875 anda
CALL -868 and my guess is that one or the other is
causing this. Is this correct? If so, are any of the old
calls still valid? Bob Schmidt
District Heights, Md
CALL -875 (clear current screen line) has not been
valid since the introduction of the Ile. Those of you
skipping from a Il-Plus to a Ilgs may have some
catching up to do. CALL -875 on the II-Plus jumps
into the middle of the screen scroll functions to clear
the current line. Apple changed these routines when
rewriting the monitor ROM for the Ile. On the ligs, the
code that replaces these routines generates the
Strange messages you've been seeing.
CALL -868 (clear to end of line) is still valid. To clear
the entire line (entirely from Applesoft) without
‘moving the cursor and with the 80-column firmware
off, try the sequence:
10 CH = PEEK(36): POKE 36,0: CALL -868: POKE 36, CH
With the 80-column firmware on, on the other
hand, the correct way to clear the current line is to
print a control-Z (CHR$(26)) to the screen (control-L,
CHR$(12), will clear the whole screen; control-K,
CHR$(LL), will clear from the cursor to the end of the
screen; and control-), CHR$(29), will clear from the
cursor to the end of the current line). That technique
is better, for compatibility reasons, than calling a
Monitor routine. Too bad it doesn’t work with the 80-
column firmware off.
Apple has published several (slightly different)
lists of Monitor addresses that it promises not to
change on future Apple models. Any CALL not on one
of these lists should be removed from your programs.
The version of the list that's my current personal
favorite is in the Apple IIc Technical Reference
Manual (3.5 ROM version) on pages 313-314.
The great Tinaja Quest
Who or what is “tinaja questing’? John D. Bishop
Kingston, Ont.
Don Lancaster often offers a “tinaja quest for two,
FO.B. Thatcher, Arizona” as the grand prize in the
contests he devises for his “Ask the Guru” column in
Computer Shopper ($21/yr, 407 S Washington,
Titusville, FL 532796 305-269-3211). | always figured
itwas something like a snipe hunt, but Dennis called
Lancaster's Apple I! Hotline number (602-428-4073)
and asked. Lancaster said he uses the phrase to get
People to call up and ask questions,
Then he said that “tinaja” is a name for natural
basins found in deserts in the Southwest U.S. (usually
these basins are private and remote; their name
comes from the Spanish word for a large earthen
vessel). Like an oasis, a tinaja may be the only
source of water and respite in a desert, so “tinaja
questing” can be a life and death matter as well as a
pleasant recreational pursuit.
While he had Lancaster on the line, Dennis asked if
there was any way to fix the Apple Writer “load file
to screen” function so that it always used the
backslash rather than the current underline character
(see November 1986, page 2.77cand February 1987,
page 3.2). Lancaster said the complete details were
in his Apple Writer Cookbook and his May 1987
Computer Shopper column (page 244), but the
essential details were—bload AWD.SYS at $2000
and then, for version 2.0, 396E:C9 5C EA; for version
2.1 3974:C9 5C EA. And if you'd like to make Apple
Writer print through a Ilgs serial port, make these
patches at the same time — for version 2.0, 4DB0:60,
4F67:10, 4F6E:13; for version 2.1, 4DC7:60, 4F7E:10,
4F85:15 (from Lancaster's March 1987 Computer
Shopper column, page 108). For the complete how,
why, and wherefore of these patches, give Lancaster
ajingle.
APDA erratic on way up
Immediately after reading your September 1986
issue I sent $20 to the Apple Programmers and
Developers Association and asked to become a
member. In December | called their office and as a
result received a receipt for my $20 and a promise
that | would soon receive a membership agreement.
form, In January | called their office and as a result
received three membership forms. | promptly signed
one and sent it right back. It is now March, and | still
don't if ama member or not.
Joining APDA seems about as difficult as getting
technical information out of Apple. Am | doing
something wrong? Is anyone else experiencing this
same kind of difficulty? Chuck Zamzow
Battle Creek, Mich.
APDA is alive and well and catching up with itself.
You're not the only one who has had a difficult time
joining, but APDA assures us you're a member. APDA
grew from no members at all in August to 7,000 by
the first of the year to 11,000 currently (and still
growing). It took awhile for APDA to gear up to the
demand. A large backlog developed in December
and January because of members signing up at the
end of 1986 to take advantage of a free book offer.
The backlog was finally cleaned up in February as
Staff was added. Shipments have been up to speed
since then, according to our colleagues at APDA.
Programs, programmers wanted
Softdisk is constantly looking for short Apple II
programs of all kinds for publication. In addition, we
expect an opening around May 1 for a programmer-
writer with extensive Apple technical background and
capability of learning C-64 and IBM-PC.
Val J. Golding, Editor-in-Chief
Magazines on Disk
4023 Greenwood Road
Shreveport, LA 71109
We get several requests a year for information on
the “best way’ for programmers to get their software
published. There are many ways, which range from
starting your own software publishing company to
donating your work to your local user group's public
domain library. In between are a number of outlets
that are often overlooked, such as Softdisk, Uptime
(Box 299, Newport, RI 02840), the Nite Owl Journal
(5734 Lamar, Mission, KS 66202), and the Apple II
magazines that print program listings.
Most people don't realize that the major cost
involved with publishing software is marketing.
Open-Apple 3.31
Salespeople, advertising, and dealer discounts are
incredibly expensive. If you decide to start your own
company you'd better either have deep pockets or
an inexpensive marketing scheme.
One such scheme, which has been very successful
with a few software packages, is “shareware.” Under
this system, you encourage users to make copies of
your disk and to distribute them to their friends.
However, by means of a screen that appears when
the program is started, you ask people who actually
use your product to send you a payment for the
program. The first product to be successfully distrib-
uted this way in the Apple II world was Bill Basham's
Diversi-DOS. Basham recently told us that about 25
per cent of his Diversi-DOS income comes from
Shareware sales,
Recently a number of shareware authors joined
together in a “programming cooperative” to get
more bang from their marketing efforts. The group is
called Living Legends Software (1915 Froude Street,
San Diego, CA 92107 619/222-3722).
Another route is to sell your software to an estab-
lished software publishing house and collect royalties
‘on sales. Or maybe you'd like to do contract pro-
gramming for an established house — Roger Wagner
Publishing (P.O. Box 582, Santee, CA 92071), for
example, is even now looking for some help from
people who owna ligs and know assembly language.
Pascal RAMdisk loader II
read with interest the letter (February 1987, page
3.5) from Keith Bernstein regarding a RAMdisk loader
for Apple Pascal 13. Here's an alternative method to
load startup files onto the RAM disk from a 3.5 inch
disk.
First, format your RAMdisk using FORMATTER
version 13 (the Pascal formatter in the ProDOS
System Utilities will not work) and transfer all the files
you want into the RAM disk manually.
Then use the T)ransfer command saying
RAMS5: MYDISK:PASCAL.BACK. The Filer will respond
with “Transfer xyz blocks?” Press “N” and specify the
number ofblocks that your data occupies on the disk;
this is found at the bottom of a catalog listing. If you
select the default size instead, the full volume, which
is mostly empty space, will be transferred. That's
rather wasteful.
To use this file, boot up Pascal as usual, then
T)ransfer MYDISK:PASCAL.BACK,RAMS:. The Filer will
respond with “Remove all files from RAMS5:?” After
pressing “Y” the RAMdisk will be loaded. You can then
press control-reset to boot up from the RAMdisk. Of
course, all this can be done from an Exec program
such as the one Bernstein wrote about in his letter.
Incidentally, you may be shocked to learn that here
in Australia the IIgs retails for around $43990 and the
Ile retrofit for about $41200.
Daryl Cheshire
Edithvale, Vic
Dennis tried this and says it gives Pascal the same
systematic RAMdisk startup/shutdown procedures
we described for other operating systems in December
1986 (“RAM Van Lines,” page 2.87). To conserve
space, Dennis suggests the RAMdisk should be
K)runched with the Filer before determining it's
block size and saving out it’s contents. And, as you
point out, this technique wipes out any files already
on the RAMdisk when a “restore” is done.
The prices you quote are about $2850 and $850 in
U.S. dollars. If your import taxes on goods from
Singapore (where the Ilgs is manufactured) aren't
3.32 Open-Apple
any higher than those in the U.S., the difference must
be freight. (Seriously, Apple is doing a magnificent
job—for a U.S. company —in developing products
fora world-wide market. Are you sure at least part of
the difference isn’t Australian taxes? There's no other
legitimate reason for that large a price difference —it
just encourages black market transactions.)
Stop double RAM load
Alan Bird's “Don't pass go” program for AppleWorks
(November 1986, page 2.75 and December 1986,
Page 2.84) has been most helpful, but | have run into
a bit of a snag with AppleWorks 2.0. This version
automatically loads itself into RAM at startup. Since |
usually already have the program on my RAMdisk,
there’s no reason to load itagain. Do you know how to
keep it from doing that without having to press the
escape key?
Harlan R. Davis
Bolingbrook, Ill.
Ty this:
10 REM **% Don’t Pass Go for RAMdIsk
20 TEXT : HOME :
25 DS=CHRS(4)
30 PRINT 0S; “BLOAD”
40 IF PEEK(6250) < > 57 THEN PRINT
“Program requires Appleliorks 2.0.” : END
45. PRINT “Patching AppleWorks”
viee 10
is writen, edited, published. and
© Copyright 1987 by
Tom Weishaar
Business Consultant —_ Richard Barger
Technical Consultant Dennis Doms
Circulation Manager _ Sally Tally
Business Manager Sally Dwyer
Most rights reserved. All programs published in Open-Apple are
public domain and may be copied and distributed without charge
Apple user groups and significant others may reprint articles from
time to time by specific written request. Requests and other
editonal matenal, including letters to Uncle DOS, shouldbe sentto:
Open-Apple
P.O. Box 7651
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Published monthiy since January 1988, World-wide prices (in US
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currently available for $2 each, bound, indexed editions of Volume 1
and Volume 2 are $14.95 each, Volumes end with the January issue,
an index for the prior volume is included with the February issue,
Please send all subscription-related correspondence to
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Subscribers in Ausiralia and New Zealand should send
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Research Li $76 Malvern Road, raha WG sist AUSTAALIA
3pen:Apple is available on disk from Speech Enterprises, PO.
00 566 Rousion Texas 11070718 467 660)
Unlike most commercial software, Open-Apple is sold in an
Unprotected format for your convenience. You are encouraged 10
make back: up archival copies or easy-to-read enlarged copies for
your own use without charge. You may also copy Open-Apple for
distribution to others. The distabution fee is 15 cents per page per
copy distributed
/ARRANTY AND LIMITATION OF LIABILITY. warrantthat mostof
the information in Open-Apple is useful and correct, although
drivel and mistakes are included from time to time, usually
unintentionally Unsatisied subscribers may return issues within
180,days of delvery for afulletund Please includea note rom your
parents or children confirming that all archwal copies have been
destroyed The untulliled portion of any paid subscription will be
‘elunded on request MY LIABILITY FOR ERRORS AND OMISSIONS
|S LIMITED TO THIS PUBLICATION'S PURCHASE PRICE in no
‘case shall | or my contributors be liable for any incidental or
‘consequential damages, nor for any damages in excess ofthe fees
paid by a subscriber
ISSN 0885-4017
Printed inthe U.S.A.
Source Mail: TCF238
CompuServe: 70120,202
50 POKE 14468,44 : REM no space bar
60 POKE 14148,208
61 POKE 14149,19 : REM no return for date
20 FOR ADR=13271 TO 13273
PL: POKE ADR,234
72 NEXT + REM no RAMdIsk preload
100 PRINT DS; “BSAVE”;F'3;”,A82000,TSYS”
Blink and it's gone
luse a C-Vue LCD screen a lot It's like eating tofu—
you eventually develop a taste for low contrast. But
the “insert” cursor in AppleWorks (the blinking
underline) is impossible to find. The “replace” cursor
never gets lost. Most of the time | use insert mode. Is it
possible to patch AppleWorks so that the insert mode
cursor is a blinking inverse block?
Tom Meyer
Highlands, NC
To replace the underline character with a new
value, use:
BLOAD APLWORKS. SYSTEM,AS2000, TS¥S
CALL -151
<addr>:<val>
3006
BSAVE APLWORKS.SYSTEM,AS2000, TSYS.
where <add?> is 2D80 for version 12, 2D8B for
version L3, or 2DA1 for version 2.0, and<vab is the
ASCII value you want for your cursor (DF gives the
underline). We tested this patch using “FF” for the
value, which gives a flashing checkerboard box for
the insert cursor, and using “20,” which gives an
inverse box. I think you'll be able to see 20 better, but
you may have trouble distinguishing it from the
replace cursor—the only difference will be that the
insert cursor blinks faster. The value for the replace
cursor itself is generated by code that also appears
to initialize other routines; we decided not to mess
with it.
AppleWorks reset
Please give us a patch for AppleWorks that makes
reset work when AppleWorks hangs. I'm looking for a
more general solution than those you mentioned at
the end of your answer to “Insert system disk and...”
in April (page 3.18)—something that would work
without MacroWorks or with PinPoint, etc. There must
be awarm start address in AppleWorks somewhere!
Thom Ryan
Toronto, Ont.
Back in June 1986, page 2.33, we published “An
AppleWorks Rescue Routine” that works with all
AppleWorks versions prior to 2.0. Ithas the advantage
of being useful after AppleWorks hangs. The other
techniques we mentioned in June involve your
doing something special before AppleWorks hangs
So that you'll be able to recover. Here's an instant
replay of the June 1986 routine, along with some
new information on how to make it work with
AppleWorks 2.0:
Press control-reset to get into the Monitor.
(IF you can’t get to the Monitor, go to jail.)
*0073:0
33 control-P return
(If this doesn’t get you 8@-colunns, go to jail.)
¥2F0:2C 63 C8 2¢ 83 CO 4c
*:33 10 <--fFor AppleWorks 1.1 through 1.3
*:27 11 G-For AppleWorks 2.0
*2F06
Vol. 3, No. 4
If the main menu appears messed up, just press
escape. Save any files you have on the desktop and
reboot after using this technique.
More mail merge categories
There is a peculiarity to the mail merge function of
Appleworks 2.0 people should know about. I couldn't
understand why some of the categories from my
database were not being picked up and inserted, as
specified, in my form letter. | then began to wonder
about the fact that the mail merge data must be
printed to the clipboard using a tables-style report.
That report format has a default platen width of 8
inches. Sure enough, changing the platen width to
something greater (e.g,, 17 inches) allowed all of my
categories to be printed to the clipboard. Changing
the characters per inch to 17 can accomplish the
same thing.
I hope that this will save someone a headache or
BHO: William J. Linville
Terre Haute, Ind.
Telephone feedback
1 want to thank Jim Hercules for his inspired
AppleWorks phone dialer (April 1987, page 3.18).
Because of his discovery that you can set up a
modem as a printer in AppleWorks, | now have an
incredibly fast and easy to use phone dialer. But
mine's in a spreadsheet file. Row 1 is aname, Row 2 is
that name’s phone number, including 1 and area
code if needed; Row 3 is the next name, Row 4 that
person's phone number, and so on. | start the phone
number with a" to make it a label so | can include
commas for pauses and dashes for readability. | can
open-apple-F(ind) the name I want to dial, use the
down arrow key to highlight the number below the
name, then print that row to the modem. I can scroll
back and forth through my phone list, insert, delete,
or make changes. Hercules’ suggestion is one of
those outstandingly useful tips that I've come to
expect from Open-Apple and its readers.
Thanks also to Tony Bond (page 3.20) for the
suggestion to copy an AppleWorks 13 SEGPR file
onto an AppleWorks 2.0 disk in order to get control-e
entered as a printer command. This seems to work.
fine, but if you're using Applied Engineering's Apple-
Works 2 Expander, you'll have to reinstall it (ituses the
‘SEG.PR file for information of its own). That means
reinstalling Super MacroWorks, too.
Uhave a suggestion for Jim Thornburg’s problems
with using date categories in his AppleWorks genealogy
data base. AppleWorks’ two-digit year just doesn’t
make it in genealogy, but dates can be effectively
manipulated manually for some very useful reports.
Enter birth dates in three categories: Birth-Year
(1860), Birth-Month (02), and Birth-Day (29). Do the
same with death dates. A chronological sort of all
records by birth date is easily accomplished using
multiple sorts—sort days first, then months, then
years. You can also print reports with calculated
categories that subtract Birth-Year from Death-Year
and Birth-Month from Death-Month to give approximate
age at death.
Another option is to enter dates ina single category
in the following format: 1875-07-22. This format sorts
nicely alphabetically in forward or reverse order. So
far I've found no need for AppleWorks’ automatic date
feature in my genealogy data base, despite its useful-
ness in other situations.
C.L. Roberts
Lafayette, Calif.