Macintosh Classic
 | |
| Macintosh Classic | |
| Specifications | |
|---|---|
| Manufacturer | Apple Computer, Inc. |
| Type | Personal computer |
| Released | 15 October 1990 |
| Discontinued | 14 September 1992 |
| Intro price | US$999 (floppy only) – US$1,499 (40 MB hard disk, 2 MB RAM) |
| CPU | Motorola 68000 @ 7.8336 MHz |
| Memory | 1 MB soldered, expandable to 4 MB with Apple's memory expansion board |
| Storage | Internal 1.4 MB floppy drive; optional internal 40 MB SCSI hard disk |
| Display | 9-inch monochrome CRT, 512 × 342 pixels |
| Sound | Four-voice, 8-bit D/A conversion, 22 kHz sampling |
| ROM | 512 KB |
| Ports / interface | 1 × ADB (mini-DIN-4); DB-19 external floppy; DB-25 SCSI; 2 × RS-422 serial (mini-DIN-8); headphone |
| Power | 100–120 V AC, 47–63 Hz, 100 W maximum |
| Dimensions | 13.2 in H × 9.7 in W × 11.2 in D (33.6 × 24.6 × 28.5 cm) |
| Weight | 16–17.1 lb (7.3–7.8 kg) without a hard disk |
| OS / Firmware | System 6.0.7 – System 7.5.5 |
| Predecessor | Macintosh SE |
| Successor | Macintosh Classic II |
| Codename | XO, Civic |
| Model no. | M0420 |
The Macintosh Classic, introduced on 15 October 1990, was the first Macintosh to sell for under US$1,000. It is a cost-reduced compact: the same 68000 at 7.8336 MHz as the Macintosh SE, a 1.4 MB floppy drive, an optional 40 MB hard disk, and — unlike the SE — no expansion slot and only one ADB port.[1][2]
Specifications
[edit | edit source]Apple's own specification pages for this family.[1]
| Item | Specification |
|---|---|
| CPU | Motorola 68000, 7.8336 MHz, 32-bit internal data bus, 256-byte instruction and data caches |
| RAM | 1 MB, expandable to 4 MB (120 ns or faster SIMMs) |
| ROM | 512 KB |
| PRAM | 256 bytes |
| Expansion connector | 44-pin connector for the optional memory expansion board, which itself carries two SIMM connectors |
| Floppy | Internal 1.4 MB; optional external 800 KB or 1.4 MB |
| Hard disk | Optional internal 40 MB; external SCSI supported |
| ADB | One port, mini-DIN-4 |
| Serial | Two RS-422 ports, mini-DIN-8 |
| Sound | Four-voice, 8-bit D/A conversion, 22 kHz sampling. The Classic does not provide true two-channel output, although a stereo jack may be used |
| Video | 9-inch diagonal, 512 × 342 bit-mapped monochrome |
| Line voltage | 100–120 V AC |
| Frequency | 47–63 Hz, single phase |
| Maximum power | 100 W |
| Dimensions | 13.2 × 9.7 × 11.2 in (33.6 × 24.6 × 28.5 cm) |
| Weight | 16–17.1 lb (7.3–7.8 kg), excluding an internal hard disk |
Memory
[edit | edit source]There are no SIMM sockets on the Classic's logic board. The 1 MB on board is soldered, and expansion happens on Apple's optional memory expansion board: 1 MB soldered plus a pair of 30-pin SIMM sockets and a configuration jumper, giving 2 MB, 2.5 MB or 4 MB.[1]
Two rules from Apple that cause most of the trouble:
- the jumper must match what is fitted — "SIMMs" or "No SIMMs";
- on a 4 MB machine the modules must be eight-chip SIMMs. Apple states that 1 MB SIMMs with fewer than eight chips will not work in the Macintosh Classic.[1]
Full procedure: Macintosh Classic Memory Upgrade Guide.
The ROM disk
[edit | edit source]The Classic is the only Macintosh that can boot from its own ROM. Holding Command-Option-X-O at startup mounts a 357 KB read-only volume named "Boot Disk" containing System 6.0.3 and Finder 6.1.x — a reference to the machine's XO codename. It is genuinely useful for diagnosis: a Classic that will not boot from a disk but does boot from ROM has a working logic board, ROM, RAM and video.[2][3]
Service manual and schematics
[edit | edit source]Apple service manual
[edit | edit source]
All the Apple service manuals are on the Apple Service Source page.
Logic board and analogue board
[edit | edit source]| Logic board | Analogue board |
|---|---|
 |
 |
Maintenance, capacitors and troubleshooting
[edit | edit source]- Macintosh Classic / Classic II General Maintenance — cleaning, the 3.6 V lithium cell and its 3.0 V replacement threshold, and what Apple does and does not publish about the rails.
- Macintosh Classic Capacitor Replacement Guide — values and positions.
- Macintosh Classic / Classic II Troubleshooting — symptom-led diagnosis.
- CRT Discharge Procedure — read before opening the case.
- Retrobrite — for the yellowed case.
Apple publishes no rail tolerance and no power-supply adjustment for this machine. Its Adjustments chapter is video and yoke work only — light meter setup, cutoff, brightness and contrast, centring, size, focus.[1] Note also that The Dead Mac Scrolls, the standard component-level reference for the earlier compacts, explicitly does not cover the Classic.[4]
Sad Mac codes are decoded on Sad Mac Error Codes and with the Sad Mac Decoder.
Related pages
[edit | edit source]References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 Apple Computer, Macintosh Classic/Classic II/Performa 200 Service Source — Specifications, Troubleshooting, Upgrades, Adjustments and Additional Procedures chapters. Hosted on this wiki: File:Classic ii.performa 200.pdf.
- ↑ 2.0 2.1 Low End Mac, Mac Classic tech specs (secondary source, used for dates, prices, codenames and the ROM disk).
- ↑ The Macintosh Easter Egg List and Low End Mac both document the Command-Option-X-O ROM disk, its contents and its 357 KB size (secondary sources).
- ↑ Larry Pina, The Dead Mac Scrolls, Peachpit Press, 1992, introduction. Hosted on this wiki: File:The Dead Mac Scrolls 1992.pdf.