Mac IIcx

Building on the success of the Mac IIx, the 1989 IIcx offered the same horsepower in a smaller case. This was made possible by eliminating 3 NuBus slots and using a smaller (90W) power supply.

Mac IIcx

Although advertised as a 32-bit computer, the Mac IIx ROMs were “dirty,” containing some 24-bit code. Running in 32-bit mode requires Mode32 (search the page for “mode32”).

“The Mac IIcx has more potential to be a breakout machine for Apple than even the original Mac II. The latter showed that Apple could slug it out, head-to-head, with the muscle machines of the DOS world. The IIcx shows that Apple has learned to fit that raw power into the world of the office.” – Jim Seymour, MacUser, August 1989.

But the breakthrough here was that Apple designed the IIcx so it could be easily manufactured without using tools.

The Mac IIcx will not boot without a good PRAM battery installed.

  • Got a Mac II or other vintage Mac? Join our Vintage Macs Group or Vintage Macs Forum.
  • Our System 6 Group and System 6 Forum are for anyone using Mac System 6.
  • Our System 7 Forum is for those using Mac System 7.

Upgrade Advice

Considering the cost of a used IIci or Quadra 700, it’s more economical to replace the IIcx than replace just motherboard – and you don’t have to worry about modifying your case to make the new motherboard fit.

  • If you’re content with performance but running out of memory, RAM is pretty affordable. Go to at least 8 MB – and buy 80ns or faster in case you upgrade to a IIci motherboard later on.
  • Consider a used Mac IIci motherboard ($10 or so). This provides almost twice the performance and the option of built-in video. If you have 80ns or faster RAM, you can drop it right into the IIci’s SIMM sockets. Note that you will have to perform surgery on your case with this motherboard upgrade.
  • LOW END MAC BEST BUY Buy a used Mac IIci (starting at less than $20 depending on configuration). For a little more than buying just the motherboard, you’ll usually get 8 MB RAM and an 80 MB hard drive. If you have more RAM in your IIcx – and it’s fast enough for the IIci – you can transfer it to the new computer. And you’ll still have your IIcx as a spare computer.
  • Quadra 700 motherboards are somewhat rare and only have two NuBus slots. For that level of performance, consider a IIci upgrade plus a 68040 accelerator (see IIci page for options). Note that you will have to perform surgery on your case with this motherboard upgrade.
  • A newer hard drive will be larger and faster than the one Apple shipped with the computer, but you won’t be able to take full advantage of that speed on such an old computer.
  • If you want to run a larger monitor, support other bit depths, or have accelerated video, check out our Guide to NuBus Video Cards. There are lots to choose from, and many of them are dirt cheap on the used market.


  • introduced 1989.03.07 at $5,369; discontinued 1991.03.11
  • code names: Aurora, Cobra, Atlantic
  • model no.: M5650
  • Gestalt ID: 8
  • addressing: 24-bit, 32-bit requires Mode32
  • upgrade path: IIci, Quadra 700 (case must be modified to make room for video port)

Mac OS

  • requires System 6.0.3 to 7.5.5

Core System

  • CPU: 16 MHz 68030
  • FPU: 16 MHz 68882
  • ROM: 256 KB
  • RAM: 1 MB, expandable to 128 MB using both 4-SIMM banks of 120ns 30-pin memory; uses only 256 KB, 1 MB, 4 MB, and 16 MB SIMMs (requires MODE 32 to go past 8 MB)


  • 2.9, relative to SE
  • 3.9 MIPS
  • 4.2, Speedometer 3
  • 0.26, Speedometer 4
  • see Benchmarks: IIcx for more details



  • Hard drive: 40 or 80 MB
  • floppy drive: 1.4 MB double-sided
  • floppy connector on back of computer


  • ADB ports: 2
  • serial ports: 2 DIN-8 RS-422 ports on back of computer
  • SCSI ports: DB-25 connector on back of computer
  • sound: 8-bit stereo
  • NuBus slots: 3


  • size (HxWxD): 5.5″ x 11.9″ x 14.5″
  • Weight: 13.6 lbs.
  • PRAM battery: 3.6V half-AA
  • power supply: 159W

Accelerators & Upgrades

  • Apple Macintosh IIci motherboard (25 MHz 68030)
  • Apple Macintosh Quadra 700 motherboard (25 MHz 68040)
  • Daystar Turbo 040 (33 MHz, 40 MHz 68040), discontinued
  • MicroMac Diimo/030 (50 MHz 68030), 64 KB cache, optional 50 MHz 68882 FPU
  • MicroMac Carrera (33 MHz and 40 MHz 68040), optional 128 KB cache
  • MicroMac 90 MHz Carrera (45 MHz 68040)

Discontinued accelerators (68030 unless otherwise noted) include the Applied Engineering TransWarp (25, 33 MHz 68040), DayStar Universal PowerCache (33, 40, 50 MHz), Radius Rocket (25, 33 MHz 68040), and TechWorks NuBus (33 MHz 68040).

Accelerator Reviews

Online Resources


  • Never connect an Apple II 5.25″ floppy drive to the Mac’s floppy port. Doing so can ruin the floppy controller, meaning you can’t even use the internal drive any longer.
  • Mode32 or Apple’s 32-bit Enabler required to access more than 8 MB RAM. (Mode32 v7.5 works with System 7.5; Apple’s enabler does not.)
  • Serial port normally restricted to 57.6 kbps; throughput with a 56k modem may be limited. See 56k modem page. For more information on Mac serial ports, read Macintosh Serial Throughput in our Online Tech Journal.
  • Internal video on the IIci and IIsi, and the Mac II mono and color video cards, will not work with multisync monitors, whether Apple or PC style. Griffin Technology made the Mac 2 Series Adapter, which works with Apple’s Multiple Scan monitors and most Mac compatible monitors. There was also a version for using VGA-type monitors on older Macs.
  • Apple discontinued support and parts orders for the IIcx on 1998.08.31. You may be able to find dealers with parts inventory either locally or on our parts and service list.

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