Hi John,
>> Those IDE boards are in fact a very simple boards.
I agree! On paper, at least. But all the chatter I've seen here w.r.t. the
flavor of 8255, mods. to the boards, and subs. for some of the standard LS
logic, leads me to believe that they are not all that straightforward.
>> Using a simple logic probe determine if the chip CS* lines is going low with
>> a write.
It is.
>> If WR* is going low etc.
It is. Everything looks OK (with a simple logic probe), but I can't see these
signals in relationship to each other (no digital logic analyzer).
>> Single step through a simple continuous write loop in RAM. Eg:-
Yep, did that. As I said, a simple loop to read from any of the 8255 ports
seems to work OK. But, I can't see any output at any of the ports using a
simple output loop. And, yes, I initialized the 8255 for input or output
before running these loops.
>> By now there are well over 100 of these boards out there. It must be some
>> glitch in your
>> system
That's what I can't understand -- my backplane (CompuPro) works fine with lots
of legacy CPU's/FDCs/etc. N8VEM serial card works great in the backplane. I'm
giving up on the CF cards for now ... can't spend any more time on this.
Roger
--
You received this message because you are subscribed to the Google Groups
"N8VEM-S100" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
