PDP-11

[Dave Wade]

> QBUS termination is a complex subject; when you have multiple backplane
> sections, connected by cables, each section has 'termination'. That's what
this
> REV11-E card is; it's also the QBUS 'out' to the card in the 780 CPU which
the
> console -11 uses to control the /780 CPU. Why it's in the middle slot, I'm
not
> sure (unless things have been moved around)?
> 

Pretty sure they have been moved..

>     > M8044ee
>     > m7946
> 
> MSV11-?? (My list doesn't contain an '-EE', but it's some sort of small
MOS
> memory, Q18)
> RXV11 (RX01 8" floppy disk controller)
> 
> In theory, the M8044-EE should be an "MSV11-DE" (not "MSV11-EE", that
would
> be an M8045-EE), but none of my documentation, including the M8044 prints,
> covers such a variant. Maybe I need to look in the /780 prints, it may be
a
> special variant for use in the /780 console machines.
> 

The back of the board says M8045 5013128DP1 32K 18bit MOS memory

>     > M8192
> 
> LSI-11/73 CPU; a nice machine, if you can eventually get it running.
You'll want
> a bunch more memory (note that the M8044/8045 cards are Q18, and so you
> can only have up to 256KB with them - they _WILL NOT WORK_ in a system
> with more than 256KB in it).
> 
> The REV-11 isn't needed in this configuration. The boot PROM for this
machine
> was actually on the card in the /780 CPU, so eventually you'll need a
> replacement - something like a BDV11 or something (they are available, and
> not too expensive).
> 

These all seem to have vanished from E-Bay at present.

 
> 	Noel