Query for dec teleprinter roms

Jonathan Gevaryahu jgevaryahu at gmail.com
Mon Sep 21 22:02:26 CDT 2015

There isn't a complete archive of these ROMs in existence currently. 
Pete Turnbull's site does contain an archive, but it isn't anywhere near 
complete. The drivers in MAME/MESS also act as a sort of archive as well.

The direct prompt of this request was the desire to get one or more of 
the dot matrix teleprinters running in MAME/MESS, the progress of which 
can be seen at 
, with the LA120, but the ROMs I have right know for the LA120 fail 
their built-in checksum test, so I'm stuck at a development impasse 
until I can get some more roms to work with (or correctly re-dumped 
copies of the existing roms).

The end result of what I'm trying to do would hopefully look something 
like this: https://www.youtube.com/watch?v=l20V7f2sM8c

On 9/21/2015 3:19 PM, william degnan wrote:

    What are you going to do with these?  Is there a ROM archive for DEC
    printer ROMs?

    On 9/21/2015 3:14 PM, Jonathan Gevaryahu wrote:
>     Does anyone have an LA36, LA120 or LAS12, LA34, LA100, or LA210
>     somewhere which they could dump the ROMs from?
>     Notes:
>     The LA36 uses several proms for its discrete cpu, and 2 character
>     set roms which I believe have an 'odd' pinout.
>     The LA120, one of the roms on the '2 rom version' is an 8k 2364 24
>     pin chip which is a bit annoying to dump, since you either need a
>     2364->2764 24->28 pin adapter, or (better) a programmer which can
>     dump MC68764 or MC68766 24-pin 8k eproms (which have the same
>     pinout as 2364). The other rom on the 2 rom version is a 2k 2316
>     24 pin chip.
>     The oldest LA120 version uses 5 roms, all 2k 2316s. The code on
>     the 5-rom version and the 2-rom version may very well be the same
>     (the first 4 2k chips consolidated to one 8k chip), I'm not sure.
>     Would be nice to get dumps of both versions.
>     The LAS12 uses different code from the LA120 and to the best of my
>     knowledge all LAS12s use 2 roms, one 8k and one 2k.
>     LA34, theres at LEAST five firmware versions, almost certainly
>     six, and possibly as many as seven. There is also a special
>     firmware for a 'rom expansion' daughterboard.
>     The 1978 LA34 "54-13374" motherboard has a bizarre Intel i8355
>     mask rom+io chip in it, plus a separate rom as well. (there are at
>     least two versions of said i8355+rom firmware). Dumping the i8355
>     is not for the faint of heart, it would likely be easier to insert
>     a 'dumping program' eprom into the single rom's socket, and use
>     the LA34's cpu to spit its own rom contents out via serial.
>     The 1980 LA34 "54-13747" motherboard lacks the i8355 and uses 2 or
>     3 mask roms or eproms on it instead (and 74xx logic for the i/o).
>     There are at least three rom revisions for this, possibly four or
>     five.
>     LA100 (AKA LW100)... I have no idea. There's definitely at least
>     one rom revision. Also to the best of my knowledge neither the
>     maintenance print set nor the technical manual for the LA100 are
>     scanned (they certainly don't appear at
>     http://bitsavers.trailing-edge.com/pdf/dec/terminal/la100/ ),
>     which makes it difficult to know.

Jonathan Gevaryahu
jgevaryahu at gmail.com
jgevaryahu at hotmail.com

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