If you are having trouble getting your PC-Retro to boot, the very best place to start is by burning the 
Landmark/Supersoft diagnostic program into a 27XXX series chip and using an adapter to install in IC socket
U-33.  The only challenge is that the diagnostics require either MDA, Hercules or CGA graphics and 
corresponding monitor.  In a pinch, you can use a CGA card with composite video output running to a 
video monitor or TV.

Go to the website run by Modem 7 for much more information about this:

http://www.minuszerodegrees.net

We have yet to see a board that can't boot the diagnostic ROM (above).  However, there is an even more basic series
of tests than can be done to see if the 8088 CPU is actually working.  These tests are included here, with a brief
explanation.  However, there is more information about the Modem7 tests on the Vintage Computer Forum.

The IBM advanced diagnostic tests are only good for use with a full system.  And in most cases, the diagnostic
'help' that is offered suggests taking the computer to a dealer, or replacing a major computer system component...
not very useful.


MTM
December, 2012
