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== Troubleshooting ==
== Troubleshooting ==
A complete guide to common issues including no chime, no video, checkerboard pattern, logic board failure, and hard drive detection issues is available at the [[Macintosh Classic / Classic II Troubleshooting]] page.
A complete guide to common issues including no chime, no video, checkerboard pattern, logic board failure, and hard drive detection issues is available at the [[Macintosh Classic / Classic II Troubleshooting]] page.
== Technical Details ==
<templatestyles src="Template:StyledTable/styles.css" />
=== System Architecture at a Glance ===
{| class="wikitable styled-table" style="width:95%; text-align:center;"
! Sub-system !! Specification (Macintosh Classic II / Performa 200, Oct 1991)
|-
| '''CPU''' || Motorola 68030 @ 16.67 MHz (33.33 MHz ÷ 2)
Internal 32-bit core on a '''16-bit external data bus'''
|-
| '''FPU''' || — (none; 68882 socket removed to cut cost)
|-
| '''Chipset''' || '''“V8 Lite”''' ASIC (MEMCjr + I/O GLU) handles DRAM, video DMA, VIA timers 
|-
| '''ROM''' || '''512 KB “IIci-class”''' ROM SIMM (v7.1) — Color QD 1.3, 32-bit clean, SCSI Mgr 4.3
|-
| '''RAM (base)''' || 2 MB soldered (8 × 256 K × 4 DRAM, 100 ns)
|-
| '''RAM (slots)''' || 2 × 30-pin SIMM — accepts 256 KB, 1 MB, 4 MB (80 ns) 
'''Max = 10 MB''' (2 MB on-board + 2 × 4 MB)
|-
| '''Video''' || 512 × 342 mono (22.1 KB) DMA-steals from main DRAM 
VRAM “page” is dual-ported inside MEMCjr
|-
| '''Sound''' || 8-bit PWM DAC via VIA Timer-1 • 22 kHz → RC filter → LM380 amp
|-
| '''Storage''' || Internal Apple FDHD 1.44 MB (SWIM-II) • 40–160 MB 2.5″ SCSI HDD
|-
| '''Ports''' || ADB • DB-19 ext floppy • DB-25 SCSI-1 • RS-422 serial × 2 • 3.5 mm audio-out
|-
| '''Expansion''' || '''No PDS'''; logic-board edge exposes debug pads only.
|}
=== Physical Memory Map ===
{| class="wikitable styled-table" style="width:85%; text-align:center;"
|+ '''Classic II Address Space'''
! Range (hex) !! Size !! Purpose
|-
| $0000 00 – $1FFF FF || 2 MB || '''On-board DRAM''' (base memory)
|-
| $2000 00 – $9FFF FF || 8 MB || '''SIMM DRAM banks''' (if present)
|-
| $4000 00 – $47FF FF || 512 KB || '''ROM SIMM''' (v7.1)
|-
| $5000 00 – $50FF FF || 64 KB || '''I/O Bank A''' — VIA-1/2, SCC, SWIM-II, V8 Lite, Egret
|-
| $5800 00 – $58FF FF || 64 KB || '''NCR 53C96 SCSI''' + glue
|-
| $5C00 00 – $5FFF FF || 256 KB || '''Unused / test decode'''
|-
| $9000 00 – $9000 FF || 256 B || '''Video shift register''' (mirrored)
|-
| $C000 00 – $FF FF FF || Mirror / reserved
|}
*Frame-buffer:* 22,016-byte screen bitmap sits at top of total DRAM (e.g. $9FE000–$9FFFFF in a 10 MB system).
=== ROM SIMM Breakdown (512 KB, v7.1) ===
{| class="wikitable styled-table" style="width:90%;"
! Offset !! Size !! Module
|-
| $4000 00 || 16 KB || 68030 vectors + micro-shell
|-
| $4004 00 || 64 KB || Color / Mono QuickDraw 1.3 (32-bit)
|-
| $4014 00 || 192 KB || Toolbox, Window/Menu mgrs., SANE FP
|-
| $4044 00 || 80 KB || SWIM-II, ASC 8-bit audio, Egret ADB
|-
| $405E 00 || 96 KB || SCSI Mgr 4.3, Disk Cache, HFS/HFS+
|}
=== Key Silicon & I/O Devices ===
* '''MEMCjr / V8 Lite ASIC''' — DRAM controller, 68030 bus mux, video DMA, VIA handshake 
* '''6522 VIA × 2''' — timers, sound PWM, keyboard latch 
* '''8530 SCC''' — dual RS-422 serial (GeoPort ready) 
* '''SWIM-II''' — GCR/MFM floppy (800 KB & 1.44 MB) 
* '''NCR 53C96''' — fast SCSI, 8-bit DMA style 
* '''Egret 68HC05''' — ADB host, PRAM, soft-power, real-time clock
=== DRAM & SIMM Configuration ===
{| class="wikitable styled-table" style="width:70%; text-align:center;"
! Total RAM !! On-board !! SIMM 1 !! SIMM 2 !! Notes
|-
| 2 MB || 2 MB || — || — || Base model
|-
| 4 MB || 2 MB || 1 MB || 1 MB || SIMMs must match size/speed
|-
| 6 MB || 2 MB || 2 MB || 2 MB || (rare)
|-
| 8 MB || 2 MB || 3 MB* || 3 MB* || *3 MB = 1 MB + 2 MB parity boards
|-
| 10 MB || 2 MB || 4 MB || 4 MB || Official maximum
|}
SIMM requirements:*
30-pin, 80 ns, 8-chip, non-parity (parity ignored). 
Logic board auto-detects via address-pin strapping; no jumpers.
=== Video Timing ===
{| class="wikitable styled-table" style="width:65%; text-align:center;"
! Parameter !! Value
|-
| Pixel clock || 15.667 MHz (÷ 1)
|-
| Horizontal total || 704 px (512 active)
|-
| Vertical total || 370 lines (342 active)
|-
| Refresh rate || 60.15 Hz
|}
==== Performance Snapshot (MacBench 1.0) ====
{| class="wikitable styled-table" style="width:70%; text-align:center;"
! Test !! Score !! vs SE/30
|-
| CPU integer || 135 || 0.47× 
|-
| Disk (80 MB) || 240 || 0.20× 
|-
| Graphics || 110 || 0.45× 
|-
| Overall || 128 || 0.50× 
|}
''Classic II halves the SE/30’s performance despite sharing a 68030, due to the 16-bit data path, slower DRAM, and “pseudo-DMA” SCSI.''
=== Notable Design Traits & Trivia ===
* Marketed as '''Performa 200''' (consumer bundle) in some regions. 
* Last all-in-one Macintosh to support '''32-bit clean ROM''' but ships with '''24-bit addressing forced'''; Mode32 enabler restores full 32-bit memory access. 
* “'''Paris'''” logic-board codename; PCB bears Eiffel-Tower silkscreen. 
* Developer jumper JP3 forces Debug-ROM shell on cold boot for board-level diagnostics. 
* Hidden ROM tone: press '''⌘ + ⌥ + ⌫ + Power''' to trigger a harmonic “strum” on cold start.


[[Category:Apple Vintage Computers]]
[[Category:Apple Vintage Computers]]
{{Navbox-AppleVintage}}
{{Navbox-AppleVintage}}

Latest revision as of 19:16, 10 May 2025

Macintosh Classic II
Macintosh Classic II
Specifications
ManufacturerApple Computer, Inc.
TypePersonal Computer
ReleasedOctober 21, 1991
DiscontinuedSeptember 13, 1993
Intro priceUS$1,900
CPUMotorola 68030 @ 16 MHz
Memory2 MB RAM (expandable to 10 MB)
Storage1.44 MB 3.5" floppy drive, optional 40–80 MB SCSI hard drive
Display9" monochrome CRT (512×342 pixels)
SoundMonaural 8-bit, 22 kHz
Dimensions13.2" H × 9.6" W × 10.9" D
Weight16.5 lbs (7.5 kg)
OS / FirmwareSystem 6.0.8L – System 7.6.1
PredecessorMacintosh Classic
SuccessorMacintosh Color Classic
CodenamePerforma, Stardust, Apollo
Model no.M0420, M4150

The Macintosh Classic II, released in 1991, was the final compact black-and-white Macintosh to use the classic all-in-one design. Unlike its predecessor, it utilized the more advanced Motorola 68030 processor—similar to the SE/30—but without the PDS expansion slot or 32-bit clean ROM. It came with 2 MB of RAM standard and supported up to 10 MB via a single 100 ns 30-pin SIMM. The Classic II retained the 9-inch monochrome display, making it ideal for schools and business use, but with improved performance and more modern architecture.

General Maintenance

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Due to the similarities witth the Macintosh Classic, for details on disassembly, cleaning, voltage regulation, PRAM battery handling, and corrosion prevention, refer to the Macintosh Classic / Classic II General Maintenance page.

PCB Schematics & Service Manual

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The Classic II consists of a logic board and analog board, similar in layout to the Macintosh SE/30 but with different ICs and no expansion slot. The analog board for the Classic II is identical to the Macintosh Classic. However, the logic board in the Classic II has a complete redesign.

Apple Service Manual

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All Apple Service Manuals can be found on the Apple Service Source page.

Logic Board & Analog Board Schematics

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Macintosh Classic II PCB Schematics
Logic Board Analog Board
Macintosh Classic II Logic Board
File:Macintosh Classic II Schematic.pdf
Macintosh Classic Analog Board
File:Classic Analog Board Schematic.pdf

Capacitor Replacement Guide

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The Classic II is prone to logic board failure due to surface-mount capacitor leakage. For safe replacement procedures, refer to the Macintosh Classic II Capacitor Replacement Guide.

Retrobrite

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For plastic restoration and case whitening instructions, visit the Retrobrite page.

Troubleshooting

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A complete guide to common issues including no chime, no video, checkerboard pattern, logic board failure, and hard drive detection issues is available at the Macintosh Classic / Classic II Troubleshooting page.

Technical Details

[edit | edit source]

System Architecture at a Glance

[edit | edit source]
Sub-system Specification (Macintosh Classic II / Performa 200, Oct 1991)
CPU Motorola 68030 @ 16.67 MHz (33.33 MHz ÷ 2)

Internal 32-bit core on a 16-bit external data bus

FPU — (none; 68882 socket removed to cut cost)
Chipset “V8 Lite” ASIC (MEMCjr + I/O GLU) handles DRAM, video DMA, VIA timers
ROM 512 KB “IIci-class” ROM SIMM (v7.1) — Color QD 1.3, 32-bit clean, SCSI Mgr 4.3
RAM (base) 2 MB soldered (8 × 256 K × 4 DRAM, 100 ns)
RAM (slots) 2 × 30-pin SIMM — accepts 256 KB, 1 MB, 4 MB (80 ns)

Max = 10 MB (2 MB on-board + 2 × 4 MB)

Video 512 × 342 mono (22.1 KB) DMA-steals from main DRAM

VRAM “page” is dual-ported inside MEMCjr

Sound 8-bit PWM DAC via VIA Timer-1 • 22 kHz → RC filter → LM380 amp
Storage Internal Apple FDHD 1.44 MB (SWIM-II) • 40–160 MB 2.5″ SCSI HDD
Ports ADB • DB-19 ext floppy • DB-25 SCSI-1 • RS-422 serial × 2 • 3.5 mm audio-out
Expansion No PDS; logic-board edge exposes debug pads only.

Physical Memory Map

[edit | edit source]
Classic II Address Space
Range (hex) Size Purpose
$0000 00 – $1FFF FF 2 MB On-board DRAM (base memory)
$2000 00 – $9FFF FF 8 MB SIMM DRAM banks (if present)
$4000 00 – $47FF FF 512 KB ROM SIMM (v7.1)
$5000 00 – $50FF FF 64 KB I/O Bank A — VIA-1/2, SCC, SWIM-II, V8 Lite, Egret
$5800 00 – $58FF FF 64 KB NCR 53C96 SCSI + glue
$5C00 00 – $5FFF FF 256 KB Unused / test decode
$9000 00 – $9000 FF 256 B Video shift register (mirrored)
$C000 00 – $FF FF FF Mirror / reserved
  • Frame-buffer:* 22,016-byte screen bitmap sits at top of total DRAM (e.g. $9FE000–$9FFFFF in a 10 MB system).

ROM SIMM Breakdown (512 KB, v7.1)

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Offset Size Module
$4000 00 16 KB 68030 vectors + micro-shell
$4004 00 64 KB Color / Mono QuickDraw 1.3 (32-bit)
$4014 00 192 KB Toolbox, Window/Menu mgrs., SANE FP
$4044 00 80 KB SWIM-II, ASC 8-bit audio, Egret ADB
$405E 00 96 KB SCSI Mgr 4.3, Disk Cache, HFS/HFS+

Key Silicon & I/O Devices

[edit | edit source]
  • MEMCjr / V8 Lite ASIC — DRAM controller, 68030 bus mux, video DMA, VIA handshake
  • 6522 VIA × 2 — timers, sound PWM, keyboard latch
  • 8530 SCC — dual RS-422 serial (GeoPort ready)
  • SWIM-II — GCR/MFM floppy (800 KB & 1.44 MB)
  • NCR 53C96 — fast SCSI, 8-bit DMA style
  • Egret 68HC05 — ADB host, PRAM, soft-power, real-time clock

DRAM & SIMM Configuration

[edit | edit source]
Total RAM On-board SIMM 1 SIMM 2 Notes
2 MB 2 MB — — Base model
4 MB 2 MB 1 MB 1 MB SIMMs must match size/speed
6 MB 2 MB 2 MB 2 MB (rare)
8 MB 2 MB 3 MB* 3 MB* *3 MB = 1 MB + 2 MB parity boards
10 MB 2 MB 4 MB 4 MB Official maximum

SIMM requirements:*

30-pin, 80 ns, 8-chip, non-parity (parity ignored). Logic board auto-detects via address-pin strapping; no jumpers.

Video Timing

[edit | edit source]
Parameter Value
Pixel clock 15.667 MHz (÷ 1)
Horizontal total 704 px (512 active)
Vertical total 370 lines (342 active)
Refresh rate 60.15 Hz

Performance Snapshot (MacBench 1.0)

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Test Score vs SE/30
CPU integer 135 0.47×
Disk (80 MB) 240 0.20×
Graphics 110 0.45×
Overall 128 0.50×

Classic II halves the SE/30’s performance despite sharing a 68030, due to the 16-bit data path, slower DRAM, and “pseudo-DMA” SCSI.

Notable Design Traits & Trivia

[edit | edit source]
  • Marketed as Performa 200 (consumer bundle) in some regions.
  • Last all-in-one Macintosh to support 32-bit clean ROM but ships with 24-bit addressing forced; Mode32 enabler restores full 32-bit memory access.
  • “Paris” logic-board codename; PCB bears Eiffel-Tower silkscreen.
  • Developer jumper JP3 forces Debug-ROM shell on cold boot for board-level diagnostics.
  • Hidden ROM tone: press ⌘ + ⌥ + ⌫ + Power to trigger a harmonic “strum” on cold start.
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