31 Dec
2003
31 Dec
'03
6:56 a.m.
On Dec 31, 14:21, Jos Dreesen wrote:
My recently acquired 11/34 has a few missing parts :
the boot proms of the M9301 and the M7850 parity board.
It does have 16K mos memory and the full programmer panel.
However, when I fire it up, I cannot halt the processor, the RUN
light
stays on.
Could this be due to the missing parts ?
Not having the parity board simply means that parity errors won't be
checked or detected. Missing the PROMs won't upset anything (except if
you try to boot it, of course).
Your problem is most likely to be a missing NPR link on the backplane.
Common problem; it's caught me out at least once. Make sure there are
no empty SPC slots; all should be occupied by dual-height grant cards
or devices that pass NPR, or a small grant card with the NPR link made
amongst the wirewrap -- between pins CA1 and CB1. The small grant
cards only link the four Bus Grant lines, not NPR.
And of course, to complement the system, I am looking
for the
following
parts :
- an unibus RL11 controller. Are these rare ?
- Some more memory.
Neither of those should be *too* hard to come by. Neither of them are
rare. What's "missing"? Just the PROMs and the parity card?
--
Pete Peter Turnbull
Network Manager
University of York