29 Nov
2014
29 Nov
'14
3:03 p.m.
l?rdag 29 november 2014 skrev Pete Turnbull <pete at dunnington.plus.com>:
On 29/11/2014 20:22, Mattis Lind wrote:
Further searching and I found the LSI-11 Systems Service Manual from August
81. It describes the various revisons of the M7264 and M7270. Originally
the chip used -5.1 V Vbb. But M7270 and rev E an onwards of the M7264 use a
-3.9 V Vbb, which implicated use of other chips. So, they are not compatble
as it appears unless I modify the Vbb generation circuit on the board.
Does anyone have a spare 23088A5 chip, maybe?
I have been browsing through some of my old Qbus
boards and found one
KD11-F (M7264) CPU with 4 k word memory, a couple of KD11-HA (M7270) , a
KDF11-A (M8186) and some assorted memory boards and some SLUs.
All CPUs seemed to work except for the KD11-F board
The M7264 board has the following chips:
CP1611B-51 2111549
CP1621B451 23001C201
CP1631B-10 23088A501
CP1631B-07 23087A501
The M7270 board has the following chips:
1611H 21-15579
3007D 23-002B5
3010D 23-001B5
2007C 23-002C4
As far as I knew, they used the same chipset with the same instruction
set, but those are clearly different. The 21-15579 is the ALU etc, the
23-xxxxxx are the microcode ROMs. Obviously you could swap the 21-15579,
but you probably can't mix-and-match the ROMs. It couldn't be that one set
is something other than a PDP-11 instruction set?
--
Pete