Jozef Bogin, Slovak engineer and hacker, has just posted this short video of a light pen – PCjr interface, and whenever we have events planning again, I really want to see it as a VJ act.

I actually used a PCjr as our family’s first computer, and I had no idea it had a light pen interface. (I vaguely remember seeing a port labeled ‘LP,’ but you grow accustomed to arcane mysteries on an IBM computer.) It seems a relatively straightforward affair with a photoresistor, but in action it’s mesmerizing – instant blood pressure lowering.

Evidently the port was even on there, but IBM never made a first-party accessory – that fell to third-party manufacturer PC Enterprises. You can read up on what to do with one of these machines if you ever manage to see it in a flea market or something:

Introduction to the PCjr., or How NOT to Destroy It!

Jozef has been working on a variety of hacks for these old beasts:

Using 8-inch diskette drives with a PC


Maybe more useful is this article, which details how to handle video signals from this entire generation of machines:

Dealing with TTL/RGBI video

Anyway, let’s please make some of these mods. It’s also a nice alternative in a way to buying new video synth equipment. Should also go well with the “pre-apocalypse prepper video studio” we should absolutely definitely build. “Endtimes Video Lab”?

You’ll find lots of other 8-bit goodies on Jozef’s GitHub:

And other stuff on his blog, including some excellent vintage stuff from Czechoslovakia and the USSR: