Apple Macintosh Plus

Introduced	January 1986
Discontinued	October 1990
Release Price	$2600.00

Exactly 2 years after the introduction of the original Macintosh, Apple released the Macintosh Plus. This was the third in the series and proved to be the most popular. This Mac solved most of the short comings of the earlier Macs. It came standard with 1 MB of RAM and was expandable to 4 MB by simply removing the 4-256K SIMMs from the RAM slots and plugging in 4-1 MB SIMMs. It was the first Mac to come with a built in SCSI port for an external Hard Drive, a feature included standard on every Macintosh model since. The Plus also sported a new expanded keyboard with a numeric keypad. All these new features now made the Macintosh a true contender in the desktop publishing market that it would soon dominate.

The Plus also marked the end of the beige colored case for all Macs. There are two versions of the Plus, the earlier version prior to 1987 came in a beige colored case and the later version (after the release of the SE in 1987) came in a platinum colored case. See the picture above of the two versions. Also the platinum Plus also marked the end of the 'signature' Macs. Every Macintosh including the beige Mac Plus has on its inside cover the signatures of the original Macintosh design team. This practice ended with the platinum case.

There are currently 4 Mac Plus computers in the museum, one of which is a platinum version. They were purchased at local thrift shops. The first was added to the museum on August 30, 1999. It came complete with a keyboard and mouse.

System Architecture		Memory
Microprocessor	68000	Standard on system board	1 MB
Clock speed	7.8336	Maximum on system board	4 MB
Bus type	Apple propriety	Maximum total memory	4 MB
Data bus width	16 bit	Memory speed and type	150 ns
Address bus width	24 bit	System board memory socket type	SIMM modules
Interrupt levels	N/A	Number of memory module sockets	4 slots
DMA channels	N/A	Memory used on system board	dynamic
Standard Features		Disk Storage
ROM size	128k	Internal disk and tape drive bays	1
Optional math coprocessor	none	Standard floppy drives	1 - 3.5 inch 800k
Parallel port type		Optional floppy drives:	1 - 3.5 inch 400k or 800k
RS232C serial ports	2-RS-232/RS-422	* 5 1/4 inch 160k	no
Mouse ports	yes	* 5 1/4 inch 1.2MB	no
UART chip used	N/A	* 3 1/2 inch 400k or 800k	1 - external
Maximum speed	N/A	* 3 1/2 inch 1.44MB	no
CMOS real time clock	yes	* 3 1/2 inch 2.88MB	no
CMOS RAM	yes	Hard disk controller included	optional scsi external
Video & Graphics		Sound
Graphics Processor		Sound Interface device
Screen size - Col x Rows		Sound generation	4 voices
Resolution - Colors/High	B&W/512 x 342 pixels	ADSR capable	no
Resolution - Colors/Low
Max colors	mono black and white	Programming language
Sprites or Missiles	no	Built in language	no
		Built in M L monitor	no
Expansion Slots		Keyboard Specs.
Total adapter slots	none	Number of keys	78
Number of 8/16/32 bit slots	none	Upper/lower case	yes/yes
		Keyboard cable length	4 foot
Physical Specs.		Environmental Specs.
* Height	13 1/2 inches	Operating voltage @ 60 Hz	105-125 VAC
* Width	9 1/2 inches	Maximum power supplied	60 watts
* Depth	10 7/8 inches	Power supply output - volts
* Weight	16 pounds 8 ounces	Power supply output - amps