Ooooh! That's really cool. My high school had one of these around 1975 or 1976, we used it before we talked them into buying an Altair. The punch card unit was pretty spiffy, I think it used 8 of the row bits? And IIRC there were instructions you could punch that were not available from the keyboard. The cards were the votamatic type: hanging chad and all. It was a lot of fun to program, and pretty interesting and complex for a calculator. I'd love to know what the memory technology was inside -- acoustic delay, static RAM, or what? =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- _| _| _| Brian Knittel _| _| _| Quarterbyte Systems, Inc. _| _| _| Tel: 1-510-559-7930 _| _| _| http://www.quarterbyte.com