#decitek

[commodorez]

Mystery blue paper tape punch in action

[commodorez]

Paper tape punch and reader debugging time

[commodorez]

QMODEM on the Commodore PC40-III running MS-DOS 5, connected via serial port to a crude simplex current loop adapter to attempt interfacing with a Decitek paper tape reader & punch.

[commodorez]

Traces.

[commodorez]

Behold, my Vintage Computer Festival Midwest 13 exhibit booth, complete with Commodore rotary phone, new Decitek paper tape reader/punch, and core memory. 

The modem under the phone was a loaner unit I didn’t get a chance to play with.  The phone however served as the “Cactus Hotline” on the PBX that connected various machines at the show, which was amusing.

I was glad to give others a chance to use the Cactus.

[commodorez]

Decitek Paper Tape Reader & Punch

I’ve shown the logic circuit boards before, but not the punch mechanism, power supply, and other aspects of the device.  This one was made probably around 1979.  The design is likely from the 1960s.  Remex made the punch, and the reader is a Decitek 262E5.

[commodorez]

My Decitek paper tape reader/punch has no microcontroller on board.  It’s purely 7400 series logic.  Shift registers, counters, analog comparitors, flip-flops, and a bunch of glue logic.  I would love to find proper documentation on how it works.  I’m told that current assessments of the interface are that it’s a simple current loop interface.