[Coladam] SmartWriter ROMs

Rich Drushel drushel at apk.net
Tue Jun 17 15:51:15 CEST 2008


On Tue, June 17, 2008 7:10 am, Troy Forsythe wrote:

> If anyone knows the socket locations for these chips, or could take a system
> apart and tell me which chips are in sockets U20, U21, U22 and U8 I would
> greatly appreciate it.

    Hi Troy, I did get your other E-mail.

    I don't have a system in pieces right now to verify what I think
I remember, so sadly, there are disclaimers for what follows.

    While there are 4 ROM sockets, there are different ways to populate
them and address them.  It depends on the manufacturing revision of the
circuit board, plus how much it may be been reworked with jumper wires
and other spaghetti.  The software revision of the SmartWriter ROM is
only an imperfect indicator of the equivalent hardware state of the the
system.

    If your SmartWriter is R57 or R59, it likely has all 4 ROM sockets
populated with 8K chips(3 for SmartWriter, 1 for EOS).  These have the
earliest circuit board revision and have lots of reworking -- these were
the original DOA ADAMs that were sent back for warranty repair after
Christmas 1983.  However, it is possible to jumper even the earliest
hardware to support other ROM size configurations.

    The French or German SmartWriter cards (that plugged into the
center expansion slot of European ADAMs, but which will not work on
North American ADAMs because needed signals are not run out to the
connector) were also 4 x 8K.  I have one each of these cards, and neither
one works in an R80 ADAM.  (They must not work for some reason in my
R59 ADAM, but I cannot remember why -- it may cause the system to crash
or something, the way that anything I attach to its sideport causes it
to crash.)  In the available schematics, you can see that the three
address select signals to the center slot are blank.  (To actually see
or run the code, I had to desolder the ROMs and put them into the regular
sockets on a working 4-ROM system).

    The "stable" system has R80 SmartWriter and 3 ROMs:  16K + 8K for
SmartWriter, and 8K for EOS, with one open socket.  There are SmartWriter
versions between R59 and R80 out there (I have seen an R77) but I don't
know how their ROM sockets are jumpered.

    *Rich*

-- 
Richard F. Drushel, Ph.D.            | "They fell:  for Heaven to them no hope
Department of Biology                |  imparts / Who hear not for the beating
Case Western Reserve University      |  of their hearts."
Cleveland, Ohio  44106-7080  U.S.A.  |         -- Edgar Allan Poe, "Al-Aaraaf"




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