Ultralite battery questions

Bryan QRV Biggers (starnet!apple!n9gbj.ampr.org!n9gbj)
Thu, 18 Feb 93 15:49:30 GMT

I just picked up a used Ultralite for $cheap, intending to use it as
a dedicated "controller" for one of my pieces of radio equipment, but I
find that the computer is so, well, cute, that I actually want to use it
for other things! My machine had 2 (well, maybe 3) problems when I got
it, and I hope that someone on this list has already solved those that
remain.

The first problem was that I didn't get a serial cable with the
unit. I was able to figure out the pinout (would have been easier if I
had found this list first), and make a cable to get going. BTW, there
seems to be some difficulty in obtaining the 9 pin connector, but I
found that the connector used for a mouse adapter worked fine; I just
hacked off the connector from an unused adapter that came with a
Microsoft mouse; there must be a million of those things lying unused.
Also, in the diagrams that I see here, the original cable did not appear
to have RI connected, although it appeared to be functional on the din
plug. It would be nice to find a source for a neatly made original cable,
though. Anyone know where I can get one?

The second and third problem(s) was/is the battery. The main battery
was dead when I got it (would not charge, only showed about 5V). I
managed to get my hands on another one (new and free!), but apparently
my machine has the "non user replaceable" battery type. This is a series
of 7 molicell AA cells in plastic wrap, with a 2 wire connector hanging
off. The original battery was behind a little removable (metal?) door.
The new battery is in a molded plastic case, with 2 metal contacts,
apparently "user replaceable". I went crazy, and soldered the connector
to the new pack, and managed to seat it and the wires in the battery
compartment (had to melt the battery case a bit with the iron to make a
channel for the wires, being ever mindful of the explosive properties
of lithium batteries). This seems to charge up and work OK, and I think
that the 2 batteries are the same type and capacity but... does anyone
know if there was ever a real modification for the Ultralite to convert
the "non user replaceable" battery machine to a "replaceable" one? It
looks as if the modification would just be a little circuit board doodad
that would plug into the small opening where the power connector is on
my machine and would give it 2 spring contacts for the new battery. I'll
call NEC, but I have a feeling that they aren't going to be much help
on a machine this old.

I have also heard mention in 2 places (in a note here in the
archives, and from a battery distributor that I called) that NEC was
going to, or did produce some kind of retro-fit package for the
Ultralite to allow it to run on a different battery type (gee, NiCads, I
hope?) Does anyone know if there is any truth to this, or is it just
wishful thinking? Sure be nice to run this off NiCads, or NiMH
batteries that should be readily obtained.

Oh OK, just one more question, it looks as if the machine could
be run off of 12V alone with a little power filtering. Does anyone know
what the 5V supply on the charger is used for? Is it only for the
external disk drive? Will the internal modem operate without the 5V?

Bryan Biggers
bryan@pgd.adp.wisc.edu