RE: C128 repair advice...
Date: 2002-02-25 09:31:28

Hallo Bo,

I can give some other advices. By tying the WAIT-input to GND you stop the
Z80. AFAIK the Z80 immediatly starts at address $0000 after a reset. As the
Z80 doesn't do anything at all now, you can use a digital Voltmeter to check
the state of various address- and controllines. Including those of a buffer
as Richard suggested.

A step further is disabling the Z80 by pulling BUSRQ Low. Now you can feed
the address- and other lines with your own signals and see if the PLA, MMU
and other ICs work as they should do.

FYI: the 8088 board has been "schematiced" for about 75%.
   / __|__
  / /  |_/     Groetjes, Ruud
  \ \__|_\


       Message was sent through the cbm-hackers mailing list

Archive generated by hypermail 2.1.1.