Sounds like you are almost there Dave. My first suspicion would be MWRT jumpers on the bus for this or some other card are not correct. Remember at any one time only one CPU card can drive MWRT. If you switch CPU’s make sure two CPU’ are not driving the line. Also check TMA0* and RFU3 on RAM card line up with switch/jumper settings.
For anybody else out there if you have built the card and have checked all obvious things and still cannot get it working using our Z80 and RAM boards I will volunteer to try and debug it for you since I understand this is a fairly difficult card for some people.
John Monahan Ph.D
From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of yoda
That is my plan as soon as I figure out why my memory board stopped working - I need to put the logic analyzer on and see what is going on - it was working - probably had one of the jumpers on cpu card that should not have been when I put in SMB and had 2 boards driving the same line and probably have blown a driver some where - should not be difficult to find I hope.
I have your monitor running and plan to do a new one all in C so that the monitor will be fairly portable across machines by just recompiling in the right target mode with gcc. I have done some testing of the C code and I have most of the details worked out so should not be long. This summer has not afforded me much time with travel and other things.
I got mine working back in June Andrew, have “written it up” here:-
The very simple 68K monitor is working fine also. What is needed is somebody to take the 8086 ROM BIOS code that reads MSDOS/CPM86 code on our 8086 boards for our IDE Board or ZFDC board and hammer it into 68K code to boot CPM 86K.
Has anyone gotten their S-100 68K CPU board V3 working?
I’d appreciate a status update. Thanks and have a nice day!