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

[voltaage]

Hello.

I just got a new TI 59 calculator from a flea maket. It came with all the master library cards as well as for an extra batch of blanks. Apart from the problems I'm facing with the power supply module, I'm curious if I can make new cards from scratch. So I thought this would be logical to do:

I've also bought a NOS VHS cassette from that market too, it is branded Sony T-120PR. I don't have any cassette players nor cassettes themselves, so I think is reasonable to sacrifice this one for making new cards for use in calculators. That's for the magnetic side. For the info side I picked thin acetate sheets. This is becasue it would glide easily into the pressure plate and also it will provide durability for several reads. I'll maybe pick some soft glue stick to join the two things together, after all, the tape is not that heavy. Of course for straight cuts I'll use a small guillotine for best results.

I haven't tested those cards because my TI is still under repair. My only concern right now is about the media density. VHS tapes have enought tpi in order to fit 240 lines per picture diagonally. In the case of my cards they should be able to fit 480 bytes across. They should work according to my logic, especially because the cassette tape is "professional" according to the label.

Have you tried to do this before with TI's/HP-65 cards?