[HECnet] pdp-11/83-84

[Dave McGuire]

On 07/05/2012 02:22 AM, Boyanich, Alastair wrote:
Quick question. I've just snaffled an M8190-AE with what I think is the
21-21853-06 FPU as an upgrade for either the 11/70 or 11/23Plus at home.

  Nice!

I've seen reference to CIS microcode for these boards about the place
and am extremely keen to have a go at it with macro. I'm not "actually"
sure if it has it in the PROMS, but being handy with a EPROM programmer
hopefully I can find it. Does anyone have any reading material on how to
figure out if the CIS microcode is installed ?

  Huh?   That's a J-11 based board, and I'm pretty sure the CIS option
for the J-11, while planned, was never actually shipped.   It would have
been two additional chip carriers on the bottom side of the big white
J11 multi-carrier chip.

  The only ROMs on a KDJ11-Bx board contain the boot/diag code, not
microcode, and conversely, the only microcode on a KDJ11-Bx (or any
J11-based board for that matter) is in the microcode ROM, which is a
part of the "control" chip, which is one the two chips on the J11
multi-chip carrier itself.   No microaddress lines or any other internal
state machine stuff is brought out to the pins of a J11.

  (sorry!)

  You CAN, however, get a CIS option (if you can find it!) for your
11/23!   I too would love to mess with CIS a bit; I've never done so.   I
have two CIS option board sets for my 11/44s but have not yet installed
them.

                        -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA