TI 59 Diagnostic Card Listing

[voltaage]

(02-08-2022 09:22 PM)Tinue Wrote:  The old roller was dissolved all over the mechanism and quite hard to clean out.

Yeah that is quite disgusting. I'm glad you found a roller that could fit the shaft.

(02-08-2022 09:22 PM)Tinue Wrote:  I made a few tests, and it appears that many of the blank cards have deteriorated.

The cards that I have written in the early 80ies are impossible to read, they all show an error after the card ran through the reader. I tried to make the reader faster and slower with the pot, but none of the settings worked.

I would not file this as a defeat yet. When I got my second 59, it had a card in the slot which had seen better days. The pencil labeling was smeared, almost unreadable, and the magnetic side had clear marks of where the head and the rollers had been. Even with that much dirt, it still read without errors

Alas, the program written was not very useful for me, so I decided to thoroughly wipe down the card. I thought (since it is pencil after all) to use a natural eraser to clean the label part of it. Although I could easily get the letters off, it left a sticky matte finish on the card; not to mention that it smeared a bit the Texas Instruments logo and degraded the yellow color (probably time had already pre-done the job on the color). It seemed unfixable, but a dry cotton cloth helped me out by removing that layer, revealing the true shiny and glossy coating of the card (like transparency film).

As for the magnetic side, just picking a cotton swab soaked with isopropyl alcohol revealed that the ferrose compound which had some small deterioration. Not that significant fortunately. After all it gave that other side the same shiny look as the label, not the original matte look as in 5.25" diskettes.

If all of that doesn't work, then you have two options: the card is bad and unfixable, or as it happened in my experience that, you should write that card many, many times in order to get the magnetic particles moving again.

(02-08-2022 09:51 PM)Sylvain Cote Wrote:  To cleanup my magnetic cards used in HP calculators (65/67/97/41/71/75), I use a:

1) Staedtler Mars Plastic Premium Eraser to remove the oxidation

Yeah I agree. Plastic Erasers would have avoided the stickiness of bread.