ADM-3A/HP 6144 Terminal Updates
ADM-3A
I just "restored" a nice brown/beige ADM-3A. I got a
new CRT for USD 50, and then noticed that this unit
didn't have lower case installed. What the "lower
case" option consisted of was a lower case 2513-type
ROM and a couple of 2102-1 chips, all of which can be
inserted into sockets on the motherboard. Problem is,
the lower case 2513 LC ROM is not readily available.
So I built an adapter to make the multi-voltage 2513
PMOS chip I had from my other ADM-3A look like a 2716
to my EPROM programmer/reader. I read the upper and
lower case chips, programmed a lower case 2716, and
made a small adapter from to make the 2716 "look" like
a 2513 in the socket, installed the chips/adapter,
flipped a few switches, and voila!
This is detailed at
http://juliepalooza.8m.com/sl/adm3a-2.htm
I don't think that this is the FIRST time that this
has been done - but it might be among the last!
HP2644A
I've finished the keyboard, and got some paint that
fairly matches what I THINK that the original color of
this unit was. A several-hour long job was the buffing
of all (all) of the keys - this made a MAJOR
difference in the appearance of the unit (the keys are
NOT supposed to be chalky yellow).
I found a source for the unusual tube - but they want
USD 225 for it! They assure me that they use a type of
acrylic between the faceplate and the safety glass
that will never yellow, separate, or grow mold. Still,
this is a lot of money, and I intend to do the
hair-raising act of heating a nichrome wire (arriving
soon) to separate the faceplate from the CRT's safety
glass/front. Assuming that I survive with minimal
injury and am capable of writing anything, I will
detail this operation on my web pages.
If anyone has $225 to spend on a tube, contact me. I
beleive that this tube was also used on HP equipment
more worthy of spending $225 on.
http://juliepalooza.8m.com/sl/hp2644a.htm
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Received on Wed Sep 18 2002 - 09:05:01 BST