PDP 11/70s For Sale

From: allisonp_at_world.std.com <(allisonp_at_world.std.com)>
Date: Fri Sep 24 14:06:54 1999

> What about a BA11-V? That's a 4 (dual-height) Q-bus slot box. I'm sure
> the backplane can be made into a Q22 one if it isn't already. Then fill
> it with a CPU card, memory, serial ports and (say) a SCSI card.... Or
> even use it with a TU58 (it's the same physical size as the TU58, and the
> units are designed to stack).

I have three all Q22ified, only need to buss 4 lines on each socket and
put terminators at the end (220/330 pair works). I have one set up with
11/23 (M8186), MSV11P (dual width 256k), DLV11j (4 serial lines), MRV11B
(Eprom card with TU58 boot).. It has a Tu58 on top. the others have 11/2
and 11/23 (with RQDX3 and 2 MXV11s).

If you want really small, falcon card which is a minimal PDP11. it's
really a complete system T11 cpu, serial, parallel, rom and ram on one
dual card with qbus expansion.

PDT 11/150 is a good classic PDP-11 from the programmers view.

> At least one DEC book claims that a PDP11 has to have either a Unibus or
> Qbus expansion bus, and that the PRO3xx and PDT11s are not PDP11s because
> of this (for all they run the same instruction srt).

Some DEC books predate their systems... ;) That view is a side effect that
DEC possessed at the time where a PDP-11 really refers to a system and the
CPU is KA11 or some such. Pro3xx is nearly Qbus with different form
factor. PDTs have no accessable bus but they definately are PDP11 if not
by virtue of the same chips use in Q and some Ubus counterparts(LSI11, F11
and J11). So what if the formfactor is a bit different. ;)

Allison
Received on Fri Sep 24 1999 - 14:06:54 BST