HP-65 more on the card reader

[wallyt]

Regarding viewing the magnetic data on a card, if money were no object one could invest in a can of Magnetic Developer from http://www.magneticdeveloper.com/product/spray-2oz

I think this would render the card useless afterward, and heaven forbid any of it gets into the reader, but it should verify data recording. Didn't HP specify something like this when servicing the card reader on a 97 to verify that track length was within specs?

Many, many years ago the Ampex company produced a similar liquid called EdiVue for viewing magnetic domains on videotape so that it could be manually edited (with scissors and splicing tape!). I had a can of this but forgot where I put it; senior moment strikes again ;0)