Macintosh Plus

Template:Mac specs The Macintosh Plus computer was the third model in the Macintosh line, introduced two years after the original Macintosh and a little more than a year after the Macintosh 512K. It originally had a beige case, but in 1987, the case color was changed to the long-lived "platinum" color.

Overview

The Mac Plus was the first Macintosh model to include a SCSI port, which launched the popularity of external SCSI devices for Macs, including hard disks, tape drives, CD-ROM drives, printers, and even monitors. Its SCSI implementation was engineered shortly before the initial SCSI spec was finalized and, as such, is not 100% SCSI-compliant (but is close). SCSI ports remained standard equipment for all Macs until the introduction of the iMac in 1998.

It had a new 3.5" double-sided 800 KB floppy drive, offering double the capacity of previous Macs along with backward compatibility. Like the 400 KB drive in earlier models, the drive used variable speed GCR, making disks written with it incompatible with PC drives. The 800 KB drive had two read/write heads, enabling it to simultaneously use both sides of the floppy disk and thereby double storage capacity.

The Mac Plus was the first of many Macintoshes to use SIMMs (single in-line memory modules) for its memory. It came standard with 1 MB of RAM (four 256 KB SIMMs) and could be upgraded to 4 MB of RAM. It had 128 KB of ROM on the motherboard, which was double the amount of ROM that was in previous Macs; the new System software and ROMs included routines to support SCSI, the new 800 KB floppy drive, and the Hierarchical File System (HFS), which used a true directory structure on disks (as opposed to the earlier MFS, Macintosh File System in which all files were stored in a single directory, with one level of pseudo-folders overlaid on them). For programmers, the fourth Inside Macintosh volume detailed how to utilize HFS and the rest of the Mac Plus's new system software.

A compact Mac, the Plus had a one-bit, nine-inch 512 by 342 pixel black & white display with a resolution of 72 PPI, identical to that of previous Macintosh models. Unlike earlier Macs, the Mac Plus's keyboard included a numeric keypad, and, as with previous Macs, it had a one-button mouse and no fan, making it extremely quiet in operation.

The applications MacPaint and MacWrite were bundled with the Mac Plus. After August of 1987, HyperCard and MultiFinder were also bundled. Third-party software applications available included MacDraw, Microsoft Word, Excel, and PowerPoint, as well as Aldus's PageMaker. This was the first time GUI versions of Microsoft Word, Excel, and PowerPoint were introduced on any personal computer platform.

The Long Life of the Mac Plus

Although the Mac Plus became overshadowed by two new Macs in March 1987 (the Macintosh SE and the Macintosh II), it remained in production as a cheaper alternative until the introduction of Macintosh Classic on 15 October 1990. This makes the Macintosh Plus the longest-produced Macintosh ever. It continued to be supported by versions of the Mac OS up to version 7.5.5.

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The long life of the Macintosh Plus power supply ended prematurely for many owners. There is an issues with the power supply solder joints becoming fractured due to a heat issue. The Macintosh Plus lacked an internal cooling fan. This was corrected with the introduction of the Macintosh SE. If the case is removed, the mylar protector removed, this will expose the solder joints. To fix the Mac Plus power supply, solder all the fractured solder joints where the power connectors come through the power supply. It may be necessary to view the solder joints with a magnifying glass to see the tiny fractures around the connector posts. The symptom is a bright vertical power line running down the center of the screen.

There is a program called vMac that will emulate a Mac Plus on a variety of platforms, including Unix, Windows, DOS and Mac OS.

Trivia

A Mac Plus made an appearance in the 1986 science fiction movie Star Trek IV: The Voyage Home. In the scene, engineer Scotty, having travelled to the 1980s from the late 23rd century, tries to use the Mac to demonstrate the formula for a material known as transparent aluminum. However, he is perplexed by its failure to respond to his voice commands. Scotty is handed the mouse, which he holds up to his mouth like a microphone and cheerfully says, "Hello computer!" The machine's owner directs him to the use the keyboard, which he calls "quaint" but quickly accomplishes the task.

A Mac Plus also made an appearance in Flubber; it is located in the main character's kitchen.

External links

• BYTE takes an early look at the Mac Plus
• Uses for a Mac Plus