Mac286
Encyclopedia
The Mac286 was a Intel 80286
-based MS-DOS
coprocessor
expansion card
for one of Apple Computer
's first expandable Macintosh computers, the 1987 Macintosh II
. It was developed by AST Research
in an effort to close the gap between the Macintosh and IBM PC
computing worlds. AST also introduced the related Mac86 card for the Macintosh SE
.
By 1989, AST had left the Apple market and sold the rights and technologies for the Mac286 and Mac86 cards to Orange Micro
. Orange Micro would later make a successful line of coprocessor cards based on the 80x86 processor family, before leaving the coprocessor market to concentrate on USB
and FireWire products.
In 1992, Orange Micro discontinued the Mac286 board. Support for the card was discontinued sometime later.
Of the three versions, the AST appears to be the most common.
The Mac286 software provides emulation of the following additional hardware:
Intel 80286
The Intel 80286 , introduced on 1 February 1982, was a 16-bit x86 microprocessor with 134,000 transistors. Like its contemporary simpler cousin, the 80186, it could correctly execute most software written for the earlier Intel 8086 and 8088...
-based MS-DOS
MS-DOS
MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...
coprocessor
Coprocessor
A coprocessor is a computer processor used to supplement the functions of the primary processor . Operations performed by the coprocessor may be floating point arithmetic, graphics, signal processing, string processing, or encryption. By offloading processor-intensive tasks from the main processor,...
expansion card
Expansion card
The expansion card in computing is a printed circuit board that can be inserted into an expansion slot of a computer motherboard or backplane to add functionality to a computer system via the expansion bus.One edge of the expansion card holds the contacts that fit exactly into the slot...
for one of Apple Computer
Apple Computer
Apple Inc. is an American multinational corporation that designs and markets consumer electronics, computer software, and personal computers. The company's best-known hardware products include the Macintosh line of computers, the iPod, the iPhone and the iPad...
's first expandable Macintosh computers, the 1987 Macintosh II
Macintosh II
The Apple Macintosh II was the first personal computer model of the Macintosh II series in the Apple Macintosh line and the first Macintosh to support a color display.- History :...
. It was developed by AST Research
AST Research
AST Research, Inc. was a personal computer manufacturer, founded in Irvine, California in 1980 by Albert Wong, Safi Qureshey and Thomas Yuen. AST's original business was the manufacture and marketing of a broad range of microcomputer expansion cards, later focusing on higher-density replacements...
in an effort to close the gap between the Macintosh and IBM PC
IBM PC
The IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981...
computing worlds. AST also introduced the related Mac86 card for the Macintosh SE
Macintosh SE
The Macintosh SE was a personal computer manufactured by Apple between March 1987 and October 1990. This computer marked a significant improvement on the Macintosh Plus design and was introduced by Apple at the same time as the Macintosh II....
.
By 1989, AST had left the Apple market and sold the rights and technologies for the Mac286 and Mac86 cards to Orange Micro
Orange Micro
Orange Micro Inc. is a now-defunct computer hardware company which made products for use with Apple computers. The company made a variety of products for many machines, ranging from the Apple II series to the Macintosh line, but is perhaps best known for making PC compatibility cards for the...
. Orange Micro would later make a successful line of coprocessor cards based on the 80x86 processor family, before leaving the coprocessor market to concentrate on USB
Universal Serial Bus
USB is an industry standard developed in the mid-1990s that defines the cables, connectors and protocols used in a bus for connection, communication and power supply between computers and electronic devices....
and FireWire products.
In 1992, Orange Micro discontinued the Mac286 board. Support for the card was discontinued sometime later.
The Mac286 hardware
There are three distinct versions of the Mac286 hardware:- The original AST version consists of a pair of full-length NuBusNuBusNuBus is a 32-bit parallel computer bus, originally developed at MIT as a part of the NuMachine workstation project. The first complete implementation of the NuBus and the NuMachine was done by Western Digital for their NuMachine, and for the Lisp Machines Inc. LMI-Lambda. The NuBus was later...
cards, joined by two ribbon cables. The first board consists of a CPU card while the second board acts as a disk controller and memory card. - The early Orange Micro version is similar to the AST version. It was reworked in some areas and contains additional circuitry, permitting memory upgrades.
- The later Orange Micro version consists of a single board with a greater degree of VLSI chips.
Of the three versions, the AST appears to be the most common.
Details
- Intel 80286 processor, operating at 8 MHz or 12 MHz, depending on version. (A 10 MHz version may also exist.)
- Socket for an optional Intel 80287 math coprocessor
- Phoenix TechnologiesPhoenix TechnologiesPhoenix Technologies Ltd designs, develops and supports core system software for personal computers and other computing devices. Phoenix's products — commonly referred to as BIOS or firmware — support and enable the compatibility, connectivity, security and management of the various components and...
286 BIOS v3.00 (This is an AT BIOS.) - 1 MB Non-parity RAM, organized as 4 256K SIMMs (640K visible to MS-DOS)
- NEC 765-based floppy controller (NOTE: Unlike most PC floppy controller boards, the circuit in the Mac286 allows for Single Density operation. This is primarily of interest to those wishing to read older CP/M diskettes with the appropriate software.)
- 37-pin port for optional external floppy (Apple 5.25" PC Drive or equivalent)
The Mac286 software provides emulation of the following additional hardware:
- CGAColor Graphics AdapterThe Color Graphics Adapter , originally also called the Color/Graphics Adapter or IBM Color/Graphics Monitor Adapter, introduced in 1981, was IBM's first color graphics card, and the first color computer display standard for the IBM PC....
or Hercules Graphics CardHercules Graphics CardThe Hercules Graphics Card was a computer graphics controller made by Hercules Computer Technology, Inc. which, through its popularity, became a widely supported display standard. It was common on IBM PC compatibles connected to a monochrome monitor . It supported one high resolution text mode and...
(switchable) - 1.44 MB Floppy drive as drive A: (if a SuperDrive is installed in the Macintosh)
- 20 MB Hard disk, stored as a file on the host Mac.
- Access to the file system of the Mac via an emulated drive D:
- 0, 1, or 2 COM ports (These are mapped to the Mac's Modem and Printer ports.)
- Printer port, emulating either an Epson MX80 or an Apple LaserWriter. (The latter is only available if a real LaserWriter is connected to the system.)