On 8/29/2017 11:43 PM, Jerry Weiss via cctalk wrote:
On Aug 29, 2017, at 9:52 PM, Douglas Taylor via cctalk <cctalk@classiccmp.org>
wrote:
I have a BA11-M box with a backplane that I am sure has been upgraded to be 22
bit addressing.
When I got this box it had an 11/23 Dual width Cpu, MXV11-AC with custom boot
ROMs and a 256KB MSV11-P memory board. The memory in the MXV11 had been
disabled so I suspect the backplane was upgraded to 22 bit.
What I want to do is put a LSI 11/2 (M7270) and/or LSI 11/03 (M7264) into this
box and construct a minimal, basic PDP11. This system would have 64kb of
memory, some kind of serial interface and an Emulex UC07 running a SCSI disk or
SCSI2SD adapter. The OS would be RT11 V5.3.
Can I operate these Cpu's in a 22 bit backplane?
If so, does anyone have spare MSV11-DD 64kb memory and DLV11 type serial cards
for sale/trade?
Micronote 5 does not list the LSI 11/2 or 11/03 processors as being compatible
with Q22.
See section II oin http://decvax.50megs.com/doc/uNotes/micronote5.html
<http://decvax.50megs.com/doc/uNotes/micronote5.html> for the details.
The upgrades to Q22 were commonly done with wire-wrap. You could unwrap the
modification.
I think I've seen those in the past. The backplane I have has something
soldered on each side of the backplane (in the rear, where the wire wrap
pins are).
The micronote says that I can't do what I want to do. The 11/2 and
11/03 Cpus use some of those address lines for something else. So I
couldn't use the UC07.
It looks like a trip down memory lane that I can't make.
