Query for dec teleprinter roms

Jonathan Gevaryahu jgevaryahu at gmail.com
Mon Sep 21 14:14:42 CDT 2015

Does anyone have an LA36, LA120 or LAS12, LA34, LA100, or LA210 
somewhere which they could dump the ROMs from?

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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