by Milo Tsukroff
My first TI-59 was stolen about 20 years ago. I finally replaced it this past Spring 2002, when I found a used TI-59 for $2.00 at a local thrift store. Amazingly, even after 20 years, 3 moves, and a house fire, I still had my TI-59 magnetic cards from my college days. (Alas, the Solid State Software cartridges seem to have disappeared.)
Another TI-59 and a couple of PC-100 printers arrived, courtesy of eBay. Now I had a battery and a power supply, so I could try out my old cards. Trying to get the 20-year-old cards to read was going to be a nightmare, I thought. Sure enough, none of the cards would read when I first tried them. They barely made it through the card reader mechanism.
Time to take the calculators apart, I thought to myself. But first, I tried cleaning the readers "the right way", following Texas Instruments' original instructions. Amazingly, with just a little bit more effort than normal, the card readers now work! They read the old cards just as well as they ever did, and I never had to touch a screwdriver.
Here's how I did it:
My tools were the TI-59 cardboard cleaning card (for the rollers) and the "official" head cleaning card.
First I tried to read a "good" card, one that I was sure was going to load, and on which I had written down what memory bank to use. The important thing is to have the number of the memory bank I want to load in the display when I press the 2nd-Load key, either 1, 2, 3, or 4. Putting a 0 in the display will auto-load to whatever bank the data was written from originally. When the load is successful, the display shows the number of the bank loaded. If it is unsuccessful, the display shows a blinking 0 until you press Clear.
(I made a mistake with one card. I thought that it was failing on the second side, which was supposed to load into Bank 2. The problem was that I started with a 0 in the display. When it finished loading side 1, which went into Bank 1, it left a 1 in the display. Then I tried loading the other side. The number 1 didn't match bank number 2 for the 2nd side, so it gave me a load error!)
The card I first tried would not load properly. So I got out the head cleaner card. The instructions say to use this card very sparingly. Apparently overuse of this card can grind the head down too much. I ran the head cleaner card through the reader just once.
Then I used the cardboard cleaning card. To use it, I held it firmly as it tried to feed through the reader mechanism. This made the rollers rub off years of crud onto the card. Not a lot came off, but it did improve the grip. Apparently it is just surface crud that keeps the rollers from gripping correctly.
The first cleaning worked for some cards, but others would still not load. I repeated the 2-step process with the head cleaner card and the cardboard cleaning card. Then I tried again.
One of the TI-59's worked very well after 2 cleaning cycles. The other one probably worked after 3 cycles. However, due to my error with bank numbers (as indicated above) I cleaned it a few extra times.
Both TI-59's read cards just fine now. It is amazing how well these little marvels of 1970's technology have held up. Good luck in cleaning your own TI-59 card reader!
COMMENT 1: I have read on other web sites that the rollers can become permanently dented over time. My two calculators appear to have held up very well. If your TI-59 does not respond to cleaning, or seems to have a dented roller, you may have to disassemble yours anyway.
COMMENT 2: If you don't have a TI-59 cardboard cleaning card, you can make your own by cutting a card out of very heavy paper, preferably card stock. If you don't have an "official" head cleaning card, I am sorry, I do not know how you could make a substitute.