I have a KDJ11-SD (M7554-SD from a DECserver 550) that uses 27256 ROMs, and
a KDJ11-DA (from a PDP-11/53) that uses 27128 ROMs. Someone emailed me the
PDP-11/53 boot ROM hex files. They're numbered 261E5.hex and 262E5.hex. I
burned these into a pair of 27128's and plugged them into the -DA board, and
it runs great.
If I plug these ROMs into the -SD, I get the slow "KDJ11-D/S 1.0" message
that means that the powerup selftest can't even get off the starting line.
I'm guessing it means a bad ROM checksum. This same board runs RT-11 and
2.11BSD great if I boot from the Andromeda UDC11 disk controller.
I tried burning these hex files into 27256 ROMs several different ways, for
example:
first half second half
---------- -----------
firmware all zeros
firmware all ones
all ones firmware <- this emulates 27128, A14 replaces PGM
all zeros firmware
You can plug a 27256 into a 27128 socket if it has been burned like case 3,
since a run-mode 27128 socket has PGM/A14 pulled high. The board will not be
able to tell the difference.
Can anyone tell me the magic key to getting the ROMs burned for the -SD?
Maybe there is a jumper that tells the board to use 27128 ROMs, but I
haven't figured that out. I've figured out all but three of the jumpers by
now.
--
Jonathan Engdahl Rockwell Automation
Principal Research Engineer 24800 Tungsten Road
Advanced Technology Euclid, OH 44117, USA
Euclid Labs engdahl_at_cle.ab.com 216-266-6409
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Received on Mon Jul 30 2001 - 18:12:48 BST