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Re: [N8VEM-S100:6179] Re: 80386 CPU Board

I think I have something jumpered wrong, or some funny interaction with the SMB.

When I use QIED I can go back and forth between 80386 and Z80 as expected.  All TMAx LED's remain off on the SMB.
This is with P36 1-2 and 3-4 on 80386 board.

If I use QOEE,01 or the "W" command I can switch from Z80 --> 80386 but can't go back to the Z80 using either QOEE,00 or QIED

If I switch the setting of K4 on SMB and jumper P36 3-4  I can go back and forth between 80386 and Z80 using the "Z" and "W" commands, only the system starts up in 80386 mode.

Could anyone using the Z80, 80386 and SMB boards confirm their jumper settings?

Thanks!

- Gary


On Monday, February 2, 2015 at 7:24:15 PM UTC-5, monahanz wrote:

My error  Gary, the V1.49 is the most up to date version I have been using.   Most recent changes are just for PM testing BTW. The core 8086 stuff really has not changed in a while.

I stuck in hardware currently. Could you carefully checkout the 80386 switching code.  I seem to remember I used the old and new ways to switch TMA 0 line.  Only the output mode will work for the SMB V2.  With a logic probe see if you are getting signals.

John




On Monday, February 2, 2015 at 8:52:34 AM UTC-8, Gary Kaufman wrote:
Thanks for checking, I'll try tonight when I get home from work.

I believe I've tried both with 1-2 and 1-2,3-4 jumpered.  I've also tried direct port access to EDh and EEh.

The latest monitor I could find on your site was V1.49

- Gary

On Monday, February 2, 2015 at 11:34:53 AM UTC-5, monahanz wrote:

Gary, just checked my board.  I can get back to Z80 from 80386 monitor (V1.84) with the “Z” command if the P36 jumper is in 1-2 position. However NOT SO if it’s in 2-3  position.  The latter is utilizing the SMB V2 to pull down TMA1 rather than the 80386 onboard port.  I will look into it, but meanwhile check software for both CPU’s. I bet there is a conflict with either the (old) IN Port option to switch CPU’s  or the newer Output a bit method.

 

John

 

 

From: n8ve...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Gary Kaufman
Sent: Monday, February 2, 2015 5:27 AM
To: n8ve...@googlegroups.com
Subject: [N8VEM-S100:6179] 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:-

 

John

 

 


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
chip.

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).

Thanks!

- Gary

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