In 1987 a company I worked for (Epoch Systems; it no longer exists) designed and built this custom 68020-based processor board for a file server. I did the Unix port (4.2bsd from vax) for this system.
A few notes for the hard core nerds. Bring up the full resolution version to see some of these details. Note: when downloading the full picture, the preview comes up quickly (and is blurry); wait for the full download.
- The main processor (MC68020) is bottom center-right.
- To the right of that is the memory management unit: XC68851. That’s supposed to be “MC” not “XC” but we were building these boards before Motorola released the final MMU chips so some of our early boards were built with the “experimental” MMU chips. I believe these made it into the field at customer sites but I’m not sure.
- There was a separate dedicated I/O processor and that’s the second MC68020 top left.
- The board was part of a custom NFS fileserver, which used optical jukeboxes and supported a whopping 30GB of storage in the base configuration; expandable up to 150GB. We called this “Infinite Storage” (really!)
- The yellow arrow stickies in various places point to areas where ECOs were done (bug fixes; this board is serial #6)
- The processor cycle was 25MHz, which was fast at the time, and the board is an early example of surface mount technology. The engineers were debating whether to use surface mount or not, but in the end that was the only way they could cram all that stuff onto the “small” form factor board. I think there were 12 layers of traces in the printed circuit board but I don’t remember for certain.