DEC M7551 question - test-drb@ccmp.vtda.org

15 Feb 2000

...
 I recently acquired a DEC M7551 (4Mb memory) board for
my 11/23+. I
installed the board, but the system traps while doing the power-on memory
test. Unfortunately, I don't have any documentation for the board and I'm
not sure if I have the jumpers/switches set correctly. It could be that the
board is just dead, but I'd like make sure before I give up. If someone
could forward me the settings, it would be greatly appreciated. 
Are you sure it's a 4 Mbyte (M7551-CA) board?  If it's a 2 Mbyte (-BA)
or a 1 Mbyte (-AA) board then it's very possible that it's jumpered
for some other starting location than zero.  And your CPU self-test
is expecting memory starting at zero.

If you can get to ODT ("@" prompt), try doing some examines of various
locations, i.e. "0/", etc., and see if you get anything.

If the board isn't responding at "0/", try higher addresses and see if
it's living there.

-- 
 Tim Shoppa                        Email: shoppa(a)trailing-edge.com
 Trailing Edge Technology          WWW:   http://www.trailing-edge.com/
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