UNIBUS M9312 ROM type identification

[Don North]

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