Intel iSBC 80/20-4 Single Board Computer

I was given an Intel iSBC 80/20-4 computer board in December 2012. I wanted to build a second machine around this processor board, replacing the iSBC 80/10 board. This is a closer match to an MDS-800. The MDS-800 was what CP/M-80 was developed on.

NS BLC 80_20-4 Picture=

The CPU card contains 4K bytes of RAM at 03000-03FFFH. It has four 1 or 2K byte EPROM sockets (i2708 or i2716) at 0000-01FFFH. The 2708s require +5V, -5V and +12V to operate while the 2716 only need +5V.

The complete hardware reference manual for the iSBC 80/10 is here.


1529 MST 4 December 2012.

This board was missing the RAM chips, so I purchased some replacements online. I am currently waiting for them to arrive.

The memory has arrived. I checked out the engineering changes to the board and found the RAM was disabled and there were some changes to the multibus interface. I reversed the RAM change to allow the RAM to operate. I have attempted to get this board to operate with no luck. I will use the 8080 probe to see what is happening.


1355 MST 13 April 2013.