STAR CASTLE repaired!

[vernimark]

I started from this condition:

http://www.youtube.com/watch?v=n9h0c9qYkZM

in some positions some vertex were drawn in a wrong position no so far from the original.

After some checks the problem was in a faulty 74194 (4-BIT BIDIRECTIONAL UNIVERSAL SHIFT REGISTERS) in position N4: Secondary accumulator, logic block 3

regards,
vernimark
www.vernimark.com/arcade

[level42]

Something tells me you used the HP comparator to find this problem

Always good to have it documented !!!

[speleo_de]

Something tells me you used the HP comparator to find this problem

Me too

BTW this tool is meant: http://pdp-8.org/tools.html#HP_10529A_Logic_Comparator

[vernimark]

Something tells me you used the HP comparator to find this problem

HAHA that's true!!

[level42]

@Marco:  I _knew_ it...must be telepathy

@Andreas....cool, I want !

[vernimark]

to say the truth I had some difficulties to understand how to troubleshoot a chip with the generic golden card (http://www.torontosurplus.com/test-equipment-1/analyzers-1/logic/hp-10529a-20005-agilent-10529a-20005-blank-boards-for-10529a-logic-comparator.html ), but it works great with the expansion (Socket adapter board with ZIF socket)

[level42]

The HP units are a lot more than 30 bucks on E-bay though !!

[Etienne MacGyver]

thats why they say "be patience"