[Techtoolslist] ADDR ERROR @ XXXXh - LOOP?

[John Robertson]

And here is a new one for me, don't recall seeing that error message 
before, nor can I find reference to it in the 9010A Operator Manual.

Pressing the MORE key gives me "ADDR BITS 0100 - LOOP?" so I assumed 
this was some sort of a decode issue and will proceed accordingly. Just 
thought I would post it here in case anyone else runs across this rare 
error message which I assume was added to the 3A ROMs in the 9010, but 
not to the manual - at least the copy I have...

(later) It was indeed a problem with some address lines. For only A7 and 
A8 when loop reading @ 0000 (easiest - all should be Low) with the 9010 
probe (set to Address) the Low light was flickering, not steady Low. 
Turned out to be a 74LS367 that had two inputs that were somehow pulling 
the lines slightly high. This did not show up when doing a ROM or BUSS 
test - only in either of the RAM tests.

FYI

John :-#)#

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