21 Sep
2015
21 Sep
'15
8:02 p.m.
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
https://github.com/mamedev/mame/blob/master/src/mess/drivers/decwritr.c
, 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