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Re: 80386 CPU Board

David and John -

I've read thru the '386 page dozens of times!

I have the SMB and can switch to the '386 board thru QIED, or output QOEE,01.  Also the "W" and "O" commands both work.  Unfortunately when I use "Z" to return the system hangs.
I can go back to the Z80 from the 6502, 8088 or 80286 boards fine. 
I have P36 with 1-2 and 3-4 jumpered.

I do think it's likely a jumpering issue, but I'll also swap out all of the 74LS74's again once my Mouser order arrives.  I've had a few flakey ones recently.

- Gary

On Sunday, February 1, 2015 at 11:02:55 PM UTC-5, monahanz wrote:
Gary I have written up a few notes/tricks on hardware debugging these types of CPU boards:-
see here:-

On Sunday, February 1, 2015 at 8:24:54 AM UTC-8, Gary Kaufman wrote:
I completed the 80386 board yesterday, and after some confusion (on my
part) getting the monitor configured and jumpered correctly on the
MS-DOS support board it's running nicely at 32mhz using an AMD 80386-33

I'm running into two issues, and wonder if anyone has encountered them.

When I try to return to the Z80 using the "Z" command it hangs.

I've tried using a TX486DLC/E-33GA but it hangs after printing the
initial monitor prompt  (at both 16 and 32mhz).


- Gary