>> One confusing thing is in what respect are we talking about read and write. In terms of the S100 bus/CPU or
>>the 8255. Let’s talk in terms of the CPU.
>> Dave since you feel the problem is just with the CPU WR* signal (particularly the 68K), then I will go back to
>>using the 74LS244 for the CPU read (S100 bus DI lines).
When I designed my 68K SBC, I had a great deal of difficulty with the 68K R/W* signal (particularly with reads, as I remember it). I was able to get a CF to work well with the Z80 (two SBC's) directly (no 8255), but the CF seems to like a clean write or read pulse, and the 68K R/W* just didn't seem to do it. I had to go with an 8255 to get the CF to work with a 68K. And it works quite well that way. Maybe that's what you need to focus on with the 68K CPU card (clean up R/W*)???