[FRAM71] Pre-Production Batch

[Hans Brueggemann]

thanks dave, that helps a lot. first of all, there is an error in my previous post regarding the jumper settings of J1, J2. please note corrections in red.
what i can see from your test results:
test 1)
a. the scope picture is showing !CE activity during a display blink. as a side note, it seems that there is an HPIL module attached to the HP-71B, which doesn't interfere with the test, though. leave as is.
b. because there is activity regardless of the bankswitch setting, the PADCHECK on CN2:1 is now a suspect.
test 2)
step b. activity at this point hints at J1: closed, J2:open (SYSRAM active, but should be SYSROM active)
step c. no activity at this point hints at J1:open, J2:closed (SYSROM active, but should be SYSRAM active)

so, actually two issues here: one logic (human, see my previous post for corrections in red) error, and the other one probably on the pad-checking on CN2:1.
it seems that you tested this on a 2CDCC mainframe, is that correct?
can you please confirm with the corrected jumper (J1, J2) settings:
test 2b showing no activity, and
test 2c showing activity as measured on your scope plot?

will be sending you a V431 with slightly modified pad-checking per e-mail.


hans