MACINTOSH HARDWARE OVERVIEW Rev 2.0 ·February 11, 1991 ./ John Atwood (rev 1, 2) Andy Poggio (rev 1) Archltectural Investigations & Modeling Functional Technology Group, Macintosh Products Apple Computer Inc. 20705 Valley Green Dr. M-S 60AR Cupertino, CA 95014 9 Apple Registered Confidential 9 Macintosh Hardware Overview February 11, 1991 TABLE OF CONTENTS 1. 2. 3. 4. 5. 6. 7. 7. 8. 9. 10. 11. 12. 13. 14. INTRODUCTION ................................................................................. 3 PROCESSOR ....................................................................................... 11 MEMORY ............................................................................................ 18 . SYSTIM EXPANSION ........................................................................ 29 ADVANCED I/O ARCHITECfURE .................................................... 33 GRAPHICS .......................................................................................... 37 VIDEO OVERIAY ................................... ~ .......................................... 40 SOUND ............................................................................................... 44 MASS STORAGE ................................................................................ 49 NE1WORKING & COMMUNICATIONS ............................................ 53 SYSTEM SUPPORT FUNCTIONS ...................................................... 58 POWER .......... ........................................... 61 APPE IX 2 - VIA BITS ........ ...... .......... ..................................... 63 . APPE IX A W, E B CK D .G S .............. 67 BIBLI s Apple Registered Confidential 2 Macintosh Hardware Overview February 11, 1991 1. INTRODUCTION This document is a summary of the Apple Macintosh CPU hardware capabilities and constraints. It can serve multiple purposes, including establishing a baseline Macintosh architecture, and to provide new hardware and software engineers at Apple a hardware review of the Macintosh. In a sense, this serves a similar purpose as the Macintosh Family Hardware Reference and the Inside Macintosh series. However, this is an Apple internal document, and thus can include proprietary information and make references to internal specifications. The common hardware features of the Macintosh are doqimented, as well as major differen~es. To keep the document small, details are left to ERSs or specifications, which are referenced in the text. Since this document is being updated within a fixed schedule, not all areas have been given equal coverage. A goal is to continue updating this, so that after several revisions, all areas are well-covered. Your feedback, both in correcting errors, and in suggesting areas to emphasize, will be very h e quali Special notes or warning tha..L-&Hee--E~ew the Mac are highlighted. This document contains highly confidential material, and should be treated with the utmost care. Do not make copies of…

Macintosh 1/0 Systems Architecture version 1.0 1/29/92 Henry Kannapell Scott Sarnikowski Architectural lnvestigations & Modeling Functional Technologies Contents Preface ·About this Document 1 lntroduction to Arioso / 1 - 1 2 ADB -Apple Desktop Bus / 2 - 1 3 Floppy / 3 - 1 ·=·==t~th. 4 LocalTalk / 4 - 1 5 Architectural Investigations & Modeling -Arioso ©1991 S® Apple Computer Confidential - Need to Know Atioso Rcv 1.0- lfl.9/92 Preface - About this Document This document contains a description and discussion of the Arioso model ofseveral Macintosh 10 subsystems. The Arioso model is intended to be a conceptual model ofIO subsystems that helps to· improve the portabilityof low-level VO software from one platfonn to another. :i~lilililil !~ ;1!il!l l l i~1~/ „/[]~/ ·41~.il. ~.i·:;~.·:_.·:a') i:_:,,_::1.: .. ::1.::..:.:.:[l..=.·..=':!:·!:..:!:!:··::i:_:'.·:;·:·:·:··::.:.::;::··.·:':.. :.: .·=.:·:. ..···:...·=:· . . .= .....:·::·.:··:·..:.•:..::......:·:.:::· ~'4! ii Architectural Inve.stigations & Modeling -Arioso ©1991 ti@ Apple Computer Confidential - Need to Know jJ Arioso Rev 1.0 - l/29ß2 What's in this Document? This document describes the important features and concepts of the Aioso VO model for Macintosh computers. This document contains the following material: • Chapter 1, "Introduction to Ariso" provides an ovelView of the Arioso model and discusses the motivation behind the Arioso Model. lt also includes a descrlption ofa new set for diagramming symlx>ls that capture the complexity of real-time algoritms. • Chapter 2, "ADB -Apple Desktop B1:l§" docum~A!$. the Arioso model for the ADB. • G.Mpter 6, "SG$.f.EßmiltlM@.mpijf:i.fS}'stems Interface" documents the Arioso model for SCSI. : :::::::~;~,\\~?::::hFlop~YO~rem ;h~ !!!~!t!::~:~::::~:r:;;:b~:~remcan srandabne. So, ü you arej@n!y inter~ted ir{SÖil read only chapter 6. In order to get a backgound an the Arioso ß.q\~l, make sure thaFyou read Chapter 1 prior to reading any of the later chapters. :=·=·====~tlt~=: ....•h :_~. ;:·1~._ :,r' ;~ ':·.1:;:,_:;;_::.:::_=·•·.:·.=··.=•.:::·,_·:.,.:·:_.:·_ .. ::.. .. ('C:J,/ •.. Architectural Investigations & Modeling -Arioso ©1991 S® Apple Computer Confidential - Need to Know üi Arioso Rcv 1.0 - 1/29192 e ~w" ~1 . :•.:.:';: •.: :;····:,.:_i·_;_ 4tf ~1t ~ : ~ . · _ = 1 . : = ~ : ' . . : i . 1 · ~ f~il::*f~fl; ( _ · . : ·..: ;:.:;.:·.:;.::::_:!_::!·' : ' .0•• '.!'!:;,._.;·::=·:·.:::·.:.:·.=·._.=.·:„:·. :.·_. . . Architectural Investigations & Modeling -Ariooo ©1991 ti@ Apple Computer Confidential-Need to Know ....... ARIOSO Chapter 1. Introduction to Arioso Henry Kannapell & Scott Sarnikowski About This Chapter chapter presents an introduction :tArio4.:lr the Macintosh Device System Tue Arioso This qf IO model is loosely based on the OSI UJ.,. sW~@fyirlgl~i&.9.tJftajor layers for each 10 device type. :~~~:~~~:~~:r:.;B!!:~~~~~~::i:~~a:~~~wswith each ®:W. ~chineJt1n~.Ne~1K~metMU{fac OS will soon represent …