Making new HP-65/TI 59 magnetic cards out of VHS tape

[Dave Frederickson]

(11-04-2021 05:59 PM)voltaage Wrote:  

(11-04-2021 12:57 PM)Dave Frederickson Wrote:  The 71/75 cards are hand-pulled - not a very precise speed, so a timing track is required. All other HP card readers use a speed-controlled motor, so a timing track isn't necessary.

As a side note, mag cards can be degaussed to wipe any stray magnetic data. This, however, should NOT be done to the hand-pulled cards as it will destroy the timing track.

Well that is unfortunate. I wonder that might be frustrating for HP 71/75 users. All of your cards need to be in excellent condition in order to be used.

Sylvain fashioned a jig to hold the cards while cleaning.
https://www.hpmuseum.org/forum/thread-16...#pid139881