Background and Identification
The Macintosh Plus, also known by the shorter “Mac Plus,“ was an update to the original Macintosh and Macintosh 512K to make the Macintosh line of computers more expandable. While the original Mac and Mac 512K feature 128 KB and 512 KB of memory respectively, the Mac Plus shipped with 1 MB. Additionally, while the previous two Macs use non-upgradeable memory, the Mac Plus includes four SIMM slots which can be populated with up to 4 MB of total memory.
The Mac Plus was the first Apple computer to use a double-sided floppy disk drive which allows users to store up to 800 KB on a 3.5-inch floppy. The computer does not have an internal hard drive, but it has a new (for the time) SCSI port on the back which you can use to connect external hard drives, zip drives, or CD-ROM readers.
The Mac Plus was originally released with a beige case, but a platinum-colored version was introduced in 1987. The computer has the words “Macintosh Plus“ (or “Macintosh Plus ED” for the education version) written on the front case. Apple offered an upgrade kit for the original Mac and Mac 512K, so some computers with the internals of a Mac Plus have the front case from an older model. To be sure, look for the words “Macintosh Plus“ and the model number M0001A on the back case.
It is safe to open the case on the computer, but do not touch the back of the monitor (called the yoke) or any capacitors near the power cable port. These areas can contain lethal voltages. Of course, disconnect the power cable first, then follow this guide on WikiHow to discharge the CRT monitor. This iFixit guide shows how to discharge the large capacitors by the power input. It’s safe to work on your Mac Plus if you follow the proper procedures: be safe, but don’t be afraid to fix your machine.
- Motorola MC68000
- 8 MHz
- Four 30-pin SIMM slots
- 4 MB maximum
- Double-sided 3.5” floppy drive (up to 800 KB disks)
- SCSI port for external storage
- 512x342 pixels
- 9 inches
- Minimum System 3.0
- Maximum System 7.5.5