Macintosh Plus
- Family
- Macintosh Plus
- Architecture
- 68K
- CPU
- 8 MHz 68000 CPU
- Clock speed
- 8
- Introduced
- January 1986
- Discontinued
home computer model by Apple
Introduced in January 1986, two years after the original Macintosh , the Mac Plus shipped with 1 MB of RAM, a new double-sided 800 KB floppy drive, and a built-in SCSI port (the first Mac so equipped). Not only was 1 MB more RAM than PC-class machines could handle, but the Plus could be expanded to 4 MB total RAM! (Earlier Macs came with a fixed amount of memory with no upgrade path.)
The SCSI bus on the Mac Plus is officially rated at 1.25 MBps/10 Mbps by Apple, although real world testing shows it to be barely over 0.26 MBps/2.1 Mbps – which is still 4x the speed of Apple’s earlier floppy port hard drive.
The Plus does not support high density floppies, but it can be used with an external high density floppy drive as long as the disks used are 800K floppies.
Specs (via Low End Mac)
- Cpu: 8 MHz 68000 CPU
- Performance: 0.87, Speedometer 3 ; 0.7 MIPS (see benchmarks )
- Ram: 1 MB, expandable to 4 MB using pairs of 256 KB or 1 MB 150ns 30-pin SIMMs (memory upgrade requires clipping one or two resistors – details online at mia.net ; cannot use two-chip 1 MB SIMMs)
- Rom: 128 KB
- Hard Drive: external SCSI
- Floppy Drive: 800 KB double-sided
- Addressing: 24-bit only
- Gestalt Id: 4
- Code Name: Mr. T
- Pram Battery: 4.5V PX 21 (a.k.a. Eveready 523, ANSI 1306AP, IEC 3LR50)
- Weight: 16.5 lb.
- Serial Ports: 2 mini DIN-8 RS-422 ports for printer and modem
- Scsi Ports: 1 DB-25 connector on back of computer, slow implementation limited to 2,104 kbps
- Power Supply: 60W
- See: Online resources and links for the Mac Plus