You can not fix anything without knowing what it is suppose to do. Chuck's idea is sound. You will not likely get much with the logic analyzer unless the processor is actually running some code.
It doesn't sound like it is. You need to check that it is. Dwight ________________________________ From: cctalk <cctalk-boun...@classiccmp.org> on behalf of Dominique Carlier via cctalk <cctalk@classiccmp.org> Sent: Tuesday, October 17, 2017 10:50:29 AM To: Chuck Guzis via cctalk Subject: Re: The SPERRY UNIVAC UTS 40 system + 8406 double-sided diskette subsystem : Restoration Hi Chuck, Yes I understand well. But the fact that the machines Z80 based were all equipped with this famous serial I/O channel A and B, I therefore thought that the principle of verification of these channels would probably be the same on this type of architecture (Z80+PIO+CTC+SIO). Therefore, there should be probably more people able to give me some useful information. Dominique On 17/10/2017 19:26, Chuck Guzis via cctalk wrote: > On 10/17/2017 04:56 AM, Dominique Carlier via cctalk wrote: >> Hi guys! >> >> Nobody here has any information to help me to solve my problem? >> Do you think I should talk about this breakdown on another forum? If >> yes, have you an address to recommend me? >> > Dominique, the probably reason that many of us don't jump in is that > you've got a tough job, given the house-numbered ICs and lack of visible > traces. > > If this were my system and I was determined to get it working, I'd > probably start by dumping and disassembling the ROMs to find out exactly > what set of program steps occur to produce the error message. > > I'd probably then write a diagnostic ROM that would allow me to probe in > detail to characterize the fault. The happy circumstance is that the > display (and possibly the keyboard) is functional.) > > Then I'd jump in with a logic analyzer or ICE to determine the exact > nature of the failure and its source. > > You can see that this is an arduous process that few are equipped to > help you diagnose remotely. > > My two cents' worth, > Chuck > >
