6 Nov
2014
6 Nov
'14
6:38 a.m.
After replacing a lot of dead National Semiconductor TTL ICs this nice
little machine from 1972-1973 is running again. It works perfectly to do
calculations and also to create programs. I also managed to both store and
restore a program written onto a home made magnetic card. Home made since I
wasn't able to find any.
There are a few issues left: The belt in the card reader is slipping a bit
so a replacement would probably be needed to get it working 100%. One
segment in the display is dead.
Anyway: Here is the writeup of the restoration:
http://www.datormuseum.se/computers/hewlett-packard/hp9810a
and here is a video-clip: https://www.youtube.com/watch?v=C9rBoWvze48
Enjoy!
/Mattis
6 Nov
6 Nov
7:19 a.m.
Mattis wrote...
---------------------------
Anyway: Here is the writeup of the restoration:
http://www.datormuseum.se/computers/hewlett-packard/hp9810a
and here is a video-clip: https://www.youtube.com/watch?v=C9rBoWvze48
Enjoy!
-------------------
That's awesome! Great job, and love the website walkthrough on the restoration! Now I
feel guilty about just tossing up pics of my microdata restoration as plain files ;)
J
11:23 a.m.
After replacing a lot of dead National Semiconductor TTL ICs this nice
little machine from 1972-1973 is running again. It works perfectly to do
calculations and also to create programs. I also managed to both store and
restore a program written onto a home made magnetic card. Home made since I
wasn't able to find any.
How did you make the card? I have a few original ones for my 9810 and 9820, but only
a few. So a way to make more would be interesting.
There are a few issues left: The belt in the card
reader is slipping a bit
so a replacement would probably be needed to get it working 100%. One
It's actually a standard O-ring, as mentioned in my repair notes. Size BS231 --
2+7/8" OD, 2+5/8" ID,
1/8" thick. The only problem I had was the minimum order quantity was 50 or
something. Yes, I do have
plenty of them around -- but packed in one of about 700 boxes from the house move.
segment in the display is dead.
That, alas, I think you have to live with.
-tony
12:56 p.m.
torsdag 6 november 2014 skrev tony duell <ard at p850ug1.demon.co.uk>
How did you make the card? I have a few original ones for my 9810 and
9820, but only
a few. So a way to make more would be interesting.
I used 150 gram paper. It is less than 9 thou paper. But it was what I
found in
the art shop. Then I used a Tesa permanent double sided tape
roller and glued two stripes of standard half inch mag tape onto the paper
strip which I cut using a sharp knife and a steel scale.
It was working quite alright in the beginning (just after I put it into hot
water which made it shrink a bit) but now the belt ( o-ring ) just slips
more and more.
Btw. The way to make the magnetic cards are also mentioned in the article.
Quite long down in it though.
2:15 p.m.
It was working quite alright in the beginning (just after I put it into hot
water which made it shrink a bit) but now the belt ( o-ring ) just slips
more and more.
It's claimed that boiling the old belt in a kettle of water will help. It will make
your tea/coffee
taste odd for many days....
More seriously, I had this problem in my 9820 (same reader) and didn't have a belt to
hand. As a
temporary kludge, I put the belt on with a twist in it (figure-of-8 shape and swapped over
the motor leads at the
tagstrip (note, you must keep the diode on that tagstrip connected the same way round to
the wires from the
PCB edge connector -- swap over the red and white wires going to the motor only). It
worked, but of course
there was more wear where the belt rubbed over itserlf.
So I replaced it. The O-ring is not hard to get...
-tony
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ard＠p850ug1.demon.co.uk -
jwest＠classiccmp.org -
mattislind＠gmail.com