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: [email protected] [mailto:[email protected]] On Behalf Of Gary Kaufman Sent: Monday, February 2, 2015 5:27 AM To: [email protected] 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:- see here:- http://s100computers.com/My%20System%20Pages/80386%20Board/80386%20CPU%20Board.htm#80386_Debugging. 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 -- 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. -- 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.
