Macintosh Plus
 | |
| Macintosh Plus | |
| Specifications | |
|---|---|
| Manufacturer | Apple Computer, Inc. |
| Type | Personal Computer |
| Released | January 16, 1986 |
| Discontinued | October 15, 1990 |
| Intro price | US$2,599 |
| CPU | Motorola 68000 @ 8 MHz |
| Memory | 1 MB RAM (expandable to 4 MB) |
| Storage | 800 KB 3.5" floppy drive, External SCSI |
| Display | 9" monochrome CRT (512×342 pixels) |
| Sound | Monaural 8-bit, 22 kHz (4-voice) |
| Dimensions | 13.6" H × 9.6" W × 10.9" D |
| Weight | 16.5 lbs (7.5 kg) |
| OS / Firmware | System 3.0 – System 7.5.5 |
| Predecessor | Macintosh 512K |
| Successor | Macintosh SE |
| Codename | Mr. T |
| Model no. | M0001A |
Historical Background
The Macintosh Plus was the third model in Apple’s Macintosh line, introduced on January 16, 1986. It shipped with 1 MB of RAM (expandable to 4 MB) and introduced an external SCSI port, significantly improving over the Macintosh 512K. Initially beige-colored (Pantone 453), the case became platinum gray in 1987. The Plus could run up to System 7.5.5, introduced SIMM memory modules, and featured an 800 KB floppy drive.
General Maintenance
For detailed general maintenance practices including cleaning, PRAM battery handling, connector corrosion prevention, and voltage adjustments, please see the dedicated Macintosh Plus General Maintenance page.
PCB Schematics & Service Manual
The Macintosh Plus features two main PCBs: the Logic Board and Analog Board. Below are detailed schematics and the official Apple service manual for the Macintosh Plus.
Apple Service Manual
Logic Board & Analog Board Schematics
| Logic Board | Analog Board |
|---|---|
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Capacitor Replacement Guide
Detailed capacitor replacement guidelines for both analog and logic boards can be found on the Macintosh Plus Capacitor Replacement Guide page.
Retrobrite
To address plastic yellowing, detailed instructions can be found on the Retrobrite page.
Troubleshooting
A comprehensive troubleshooting guide addressing no power, chime but no video, intermittent operation, Sad Mac errors, and floppy drive problems is available on the Macintosh Plus Troubleshooting page.