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TU58 XXDP on PDP-11/05 with 8KW?

AK6DN

Veteran Member
Joined
Aug 23, 2010
Messages
980
Location
Silicon Valley USA
Sheesh, Don - have mercy!
I'll send you the ROM Real Soon Now (tm).

Just kidding. I don't really need the physical PROM, just the 64W octal image dump would do, if you can put in in an M9312 and use ODT to dump the bits.

Otherwise I can read the physical prom as a hex file and disassemble the bits back to source (I wrote some tools to do that for all the other PROM images).

Don

As an aside, I suspect it is similar to the MSCP DU boot prom, but I tried writing an MU version based on documentation, and just could not get it to fit in 64W.
So I am technically interested in what shortcut(s) DEC could take to get the MSCP command sequence for booting from an MU device.
There may just be some magic pattern you shove into a register to make it happen. Just guessing. IDK.
 

AK6DN

Veteran Member
Joined
Aug 23, 2010
Messages
980
Location
Silicon Valley USA
Not to worry - no offense taken. I don't have anything to run it in or read it on, but I'll send the board off to you this week.

I don't need any board, just the single MU boot prom (probably an 82S131 or similar 512x4 footprint compatible device). I'll just plug it into my PROM programmer and read it (an EEtools TopMaxII).
 

bqt

Veteran Member
Joined
Sep 15, 2019
Messages
506
Location
Zurich, CH
Just kidding. I don't really need the physical PROM, just the 64W octal image dump would do, if you can put in in an M9312 and use ODT to dump the bits.

Otherwise I can read the physical prom as a hex file and disassemble the bits back to source (I wrote some tools to do that for all the other PROM images).

Don

As an aside, I suspect it is similar to the MSCP DU boot prom, but I tried writing an MU version based on documentation, and just could not get it to fit in 64W.
So I am technically interested in what shortcut(s) DEC could take to get the MSCP command sequence for booting from an MU device.
There may just be some magic pattern you shove into a register to make it happen. Just guessing. IDK.

Some rumor had it that you wrote a magic sequence into the CSR for the TMSCP, yes. A vague memory of mine is that it was the word for "MU". But that is all hearsay. I have never seen the actual rom.
And I know that others have also tried and failed to get the code to fit in 64 words. :)
 

Joerg Hoppe

Experienced Member
Joined
Nov 10, 2014
Messages
91
Location
Goettingen, Germany
Hi all,

And FYI the very first entry in the table on http://www.ak6dn.com/PDP-11/M9312/ is the source/listing code for the M9312 console ODT ROM for the 11/04-34 series CPUs.

Don

UniBone emulates now the M9312 bootstrap ROM card.
Each of the 5 ROMs can be loaded with MACRO11 listings files from
http://www.ak6dn.com/PDP-11/M9312/
The tricky bootvector redirection logic is also implemented.
The address to execute after power-on is given as symbolic MACRO11 label.

For demonstration the script "m9312+xxdp_dl0.sh" is given,
which boots into 11/34 console emulator, or auto-boots XXDP from RL02.

kind regards,
Joerg
 

Dare

Experienced Member
Joined
Dec 28, 2015
Messages
66
Wow, Joerg! This is great! And barely over a month since my inquiry on the UniBone group. Talk about Ask and ye shall receive!

Now if only snail mail would hurry up and deliver my UniBone to me.

Thanks for making this happen.

--Jay
 

AK6DN

Veteran Member
Joined
Aug 23, 2010
Messages
980
Location
Silicon Valley USA
Sheesh, Don - have mercy!
I'll send you the ROM Real Soon Now (tm).

Thanks Jack!

I got the board today, pulled the MU boot prom, read it, and converted it back to source/listing/hex file for the device.

The results have been uploaded to my site: https://www.ak6dn.com/PDP-11/M9312/ and are under the 23-E39A9 'MU' boot device entry.

Surprisingly (or maybe not) there is no magic sequence or anything like that. Basic TMSCP commands but not as complete as most toggle-in bootstraps. Ie, there is no 'rewind' command given, just go ONLINE and READ blocks. So this boot PROM is not quite as robust as is, for example, the SIMH boot code for MU.

Don

And FYI if anyone needs any device boot PROMs I have blank NOS devices where I can program any device from my website using an EEtools TopMaxII programmer.
Also have lots of the common devices (DL, DY, etc) from DEC boards available. Nominal cost of $5 per device plus shipping for anyone interested.
 

bqt

Veteran Member
Joined
Sep 15, 2019
Messages
506
Location
Zurich, CH
Thanks Jack!

I got the board today, pulled the MU boot prom, read it, and converted it back to source/listing/hex file for the device.

The results have been uploaded to my site: https://www.ak6dn.com/PDP-11/M9312/ and are under the 23-E39A9 'MU' boot device entry.

Surprisingly (or maybe not) there is no magic sequence or anything like that. Basic TMSCP commands but not as complete as most toggle-in bootstraps. Ie, there is no 'rewind' command given, just go ONLINE and READ blocks. So this boot PROM is not quite as robust as is, for example, the SIMH boot code for MU.

Don

And FYI if anyone needs any device boot PROMs I have blank NOS devices where I can program any device from my website using an EEtools TopMaxII programmer.
Also have lots of the common devices (DL, DY, etc) from DEC boards available. Nominal cost of $5 per device plus shipping for anyone interested.

Interesting. So the rumors were all false. :)
And actually, an MU prom could be rather useful for Update's PDP-11/70, which nowadays only have a TU81 connected. We do have a TU77 around, but it would require some work to get it in order. And I do worry that an accident would happen that would require me to recover the system without a working disk...
But already just having the code makes it much easier to do a recovery through the front panel to start with.

But maybe I should ping you offline...
 

AK6DN

Veteran Member
Joined
Aug 23, 2010
Messages
980
Location
Silicon Valley USA
An additional FYI I found actual 23-E32A9/23-E33A9 'XE' DELUA/DEUNA net boot devices that I had previously acquired (and misfiled).
I read these and converted to source/listings/hex files are they are now up on the website under: https://www.ak6dn.com/PDP-11/M9312/

Don

Interesting note: The embedded CRC-16 (the last word of the PROM) is incorrect in both these devices. It seems to be incorrectly computed. I don't know if this was by accident or on purpose, but that is the case. I left the CRC-16 in the source/listing as it is in the original physical devices I read. The only place these words appear to be used are in the M9312 diagnostic which reads and computes the CRC-16 value for each PROM, and compares it to what is stored in the last word of the PROM. The diagnostic will fail on these two PROMs. I just add this as a historical note at this point.

Don
 
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