10 May
2012
10 May
'12
5:38 p.m.
On May 10, 2012, at 8:24 PM, Seth Morabito wrote:
Here's a puzzler.
One of the two memory boards from my PDP-11/35 is short four ICs. See:
http://www.loomcom.com/projects/pdp11-35/ms11_j.jpg
It looks like it was an 8KW board that was user-expanded to 16KW, and if
I'm reading the switches correctly it was configured for starting
address 000000. (The other 16KW board I have is configured to start at
address 100000)
Those four missing ICs seem weird, though. The other board is is fully
populated. Were they just pulled before the PDP was trashed? Or is that
a valid configuration?
Looks like they didn't populate the ninth chips (used for parity).
Someone more knowledgeable about Unibus than I would have to guess what
difference that might make.
- Dave
