Using the HP-75D Barcode Reader

[Martin Hepperle]

(03-31-2022 10:03 AM)vassilisprevelakis Wrote:  Hi Martin,

you wrote:
> The wand needs a reflective black/white surface because of its own LED light source.

I remember back in the 80s when I placed my HP 82153 wand over the caps lock LED of my BBC micro and then wrote a program to blink the LED and this allowed me to send data and programs from my BBC micro to my HP-41.

Lots of free time back then !!!

**vp

http://www.series80.org

Ah, so you are the one who built the foundation of the old optical TAN system still available in some online banking systems. They have only increased the number of blinking bars to 5 ;-)
[attachment=10490]

Also, see this thread for the HP-41C solution "PGB".

PS: I have updated the 3of9.c program in the attachment in post #1 as it was missing a final "showpage" which resulted in a missing final page of a multi-page barcode Postscript document.