On 9/6/2016 11:55 PM, Don North wrote:
On 9/6/2016 9:23 AM, JP Hindin wrote:
Greetings;
My googlefu is failing me and I was wondering if someone might be able to
help me identify one of the boot ROMs present in an M9312 bootstrap/term
board. The board has three ROMs, an RX01 (042130), an RX02 (042131) and then
a mystery code - 043127.
The M9312 ROM identification table does not list this ROM code - I suspect it
_might_ be for a DSD combined 8" drive and Winchester disk box, but I'm under
the impression this would appear as a DU device, and attempting to boot from
DU gets an ILL CMD, suggesting otherwise. I tried all of the other possible
mnemonics listed in the M9312 manual, so it doesn't appear to piggy-backing
on any of those either.
My thanks;
- JP
Octal word 042130 decodes as ascii "DX", which is the M9312 boot mnemonic for
the RX01 drive/RX11 controller combo.
Octal word 042131 decodes as ascii "DY", which is the M9312 boot mnemonic for
the RX02 drive/RX211 controller combo.
Octal word 043127 decodes as ascii "FW", which is not a standard M9312 boot
mnemonic. Probably a third party manufacturer custom boot prom.
FYI the above octal words are programmed in the first word of each boot PROM,
so they are accessible at locations 773000,
You can find program listings and hex PROM images of all the known M9312
devices here: http://www.ak6dn.com/PDP-11/M9312/, including the DX and DY PROMs.
Don
Whoops I sent before finishing this line:
FYI the above octal words are programmed in the first word of each boot PROM, so
they are accessible at locations 773000, 773200, 773400, 773600 as 18b UNIBUS
address.
Don
