Apple Macintosh II

Apple Macintosh IIThe Macintosh II was designed by hardware engineers Brian Berkeley (monitor) and Michael Dhuey (computer). A basic system with 20 MB drive and monitor cost about $5200. A color-capable system , including monitor, video card, memory and Hard Drive could cost as much as $10,000. This high end price placed it in the workstation bracket, competing directly with Silicon Graphics, Sun Microsystems and Hewlett-Packard- all of which used the Unix system. By comparison, the Macintosh II ran the single user Macintosh System. While the hardware features were comparable to workstation-class systems, the OS features placed it more squarely in competition with i386 based PCs and the Amiga 2000.  The Macintosh II was eventually replaced by the Macintosh IIcx


The Apple Macintosh II features a 16 MHz 68020 processor with 1 MB of RAM, a SCSI hard drive Macintosh II Motherboardand the option of an Apple Macintosh II video card in a relatively easy-to-expand desktop case. The Macintosh II was nicknamed the “Open Mac” because of its 6 NuBus slots which made expansion and customization easy (ergo- it was constantly being opened up to upgrade it). The Macintosh II was also the first color Macintosh and set a new standard for color in the computer industry.


The Mac II requires 30 pin SIMMs with an access speed of 120ns.  PAL SIMMs must be installed for 4 MB and larger capacities.

The ROM Is “32-bit dirty” and by default, the Macintosh II with its original ROM only supports 8 MB of RAM (1 MB SIMMs in each of eight slots). With the FDHD upgrade kit, the system is capable of supporting 68 MB of RAM (1 MB SIMMs in bank A and 16 MB SIMMs in bank B). However, with 32-bit addressing and the MODE32 system extension this model will support 128 MB of RAM (16 MB SIMMs in all eight slots).


The Macintosh II incorporated either a 40 or 80 MB hard drive on it’s internal SCSI interface.  The release of this Mac was prior to the introduction of the 3.5″ standard for Hard Drives and this unit used a 5.25″ drive.  With it’s dual 800k floppy drives, no space was available for additional drives.


The first mac to have no on-board video, the Macintosh II required a video card to provide output to a screen.  It’s mothboard incorporated SCSI (DB-25), Apple Desktop Bus (ADB), 2 DIN-8 serial ports for Printer and Modem and a single mono (8 bit) sound output port.

Video & Graphics:

The standard video card options for the Macintosh II had either 256k or 512k of VRAM and supported multiple resolutions with the most common being 512×384 and 640×480. The Macintosh II can support multiple displays  using multiple video cards in NuBus expansion slots.  Portrait (vertical orientation) displays also were popular.

Available Variations:

At the time of it’s release, the Macintosh II was available in a number of different custom configurations:

  • M5333 refers to a configuration with 1 MB of RAM and a single 800k floppy disk drive.
  • 1 MB of RAM, an 800k floppy drive and a 40 MB hard drive is order number M5430
  • 4 MB of RAM, an 800k floppy drive, and a 40 MB hard drive is order number M5410.


Third-party upgrades and accelerators were available including the Sonnet Allegro Macsonnet allegro 33mHz 68030 II processor upgrade card.  Featuring a 33 MHz 68030 processor and a PMMU, it allows installation of additional memory and the use of virtual memory software. The card plugs into the CPU socket, replacing the original 68020 processor.

A logic board upgrade to a Macintosh IIfx was also available for the Mac II. Further to the memory limitations highlighted above, the ROM on the Mac II is 32-bit dirty and Mode32 is required to use more than 8 MB RAM without any further hardware upgrades.  However only 1 MB SIMMs can be used in Bank A, limiting RAM to 68 MB. However, by incorporating Macintosh IIx roms into this Mac, 128MB ram can be addressed.

Introduction Date: March 2, 1987 Discontinued Date: January 15, 1990
Processor Speed: 16 MHz Processor Type: 68020
Details: This model has a 32-bit processor and a 32-bit data path.
Processor Upgrade: Third-Party* FPU: 68881
System Bus Speed: 16 MHz Cache Bus Speed: N/A
ROM/Firmware Type: Macintosh ROM ROM/Firmware Size: 256k*
L1 Cache: 0.25k L2 Cache: N/A
RAM Type: 30-pin SIMM* Min. RAM Speed: 120 ns
Standard RAM: 1 MB, 4 MB Maximum RAM: 128 MB*
Motherboard RAM: None RAM Slots: 8*
Video Card: Video Card VRAM Type: Video Card
Standard VRAM: 256k, 512k Maximum VRAM: 256k, 512k
Display Support: Up to 6 Displays Resolution Support: 512×384, 640×480
Standard Hard Drive: 40 MB, 80 MB Int. HD Interface: SCSI
Standard Optical: None Standard Disk: 800k x2 (Auto)
Standard Modem: None Standard Ethernet: None
Expansion Slots: 6 NuBus Expansion Bays: None
Case Type: Desktop Form Factor: Macintosh II
Apple Order No: M5333 Apple Subfamily: Macintosh II
Apple Model No: M5000 Gestalt ID: 6
Battery Type: 3.6V Lithium x2* Battery Life: N/A
Original Mac OS: 2.0 Supported Mac OS: 2.0-7.5.1, 7.5.3-7.5.5
Details: Earlier and later versions of the Macintosh System/Finder and Mac OS are not supported.
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