TI 59 Diagnostic Card Listing

[Tinue]

(02-03-2022 08:52 PM)voltaage Wrote:  Did you use ferrofluid to take the picture?

Yes, I did. A few years ago I had the idea to possibly read out these magnetic cards optically, and do some sort of OCR to retrieve the data. As the picture shows, the resolution that can be achieved with ferrofluid is not good enough. The picture is the best one of many attempts, by the way.

I somewhat successfully restored the card reader of a TI-59, but it still only writes and reads back successfully maybe one in five cards. As for reading my old cards, the success rate is almost zero.

Maybe a better attempt would be to read the amplified raw magnetic flux data right at the op amp with an Arduino and try to recreate the bits this way, but in the end it's probably not worth the effort.

(02-03-2022 08:52 PM)voltaage Wrote:  The second side clearly reveals the "77" step test, in its four track glory.

Right, I forgot: This is mentioned in the manual. Steps 240-479 all contain code "77".