The MCA ID's Page

Most of you will probably be asking yourself at this point, what the sam heck is MCA, anyhow? Well, MCA stands for Micro Channel Architecture, and is a system expansion bus that was found in a range of IBM computers, collectively known as the PS/2 series, developed around 1987-1990 or so. The most famous units are possibly the PS/2 Model 70 and PS/2 Model 80. The PS/2 series gave us the mini-DIN connector which is still used most popularly on keyboards and mice today, some 16 years or so later!

MCA was the early forerunner of PCI, and marked the first time that a true Plug and Play architecture was attempted on the x86 PC platform (1987!!). For that reason alone, MCA should be remembered. It set most of the standards (in concept, at least) which the modern PC is founded on today. IBM effectively killed MCA by keeping the bus's specifications secret, and charging huge fees for licensing it's use to third parties, plus demanding NDA's on all released info.

All MCA expansion cards have a 4 byte signature to uniquely identify them. Here is a list of known signatures, which may help those who still run OS/2 or have the awful job of troubleshooting these beasts. The signatures can be read by booting the machine with the IBM reference disk for the model in question.

Click to download the MCA IDs list, MCADEVS.TXT.