The M88 Computer

Features

Built around the Intel 8088 CPU, running at 4.77 MHz

Sockets for 640K of RAM in banks of 128K

3 8-bit ISA card slots

ATX power connector and Micro-ATX form factor - use an off-the-shelf ATX power supply and PC case!

PS/2 keyboard and mouse ports

An ATTiny to take care of system resets and ATX power signals

Primarily designed using discrete logic in 74-series ICs

Upcoming Features

The next revision of the M88 design is well and truly underway with tweaks based on real-world usage of the computer.

System clock bumped to 8 MHz
Support for an additional (but optional) 128K of RAM at E000:0000 for DOS upper memory blocks
Built-in ATX fan headers
Built-in I2C bus with STEMMA connectors to easily integrate with external devices
One more ISA card slot
Logic simplifications
Removal of the second 8259 Interrupt Controller that was serving limited purpose

Gallery

The M88 Computer running Civilization

An early prototype for initial design qualification

An earlier revision of the M88 Computer with a mess of testing wires

A previous revision undergoing testing with bodge wires

Why?

The M88 is a hobby project that seeks to build a modern computer that is compatible with the software and hardware of the late 1980s. I originally set out to build a computer that could support Sid Meier's Civilization, and achieved just that. Now, the project has expanded to explore more possibilities, such as experimenting with I2C bus connectivity to mix modern I2C devices with retro software.

Development Log and Manual

You can read more about the development of the computer in this development log.

You can also read the (work-in-progress) manual for the computer, which includes a reference for the hardware and software of the M88.

Additional M88 Peripherals

Throughout the development of the M88, I've designed a few peripherals to help with development and testing.