Classic computing fanatic Fred Jan Kraan has designed a serial adapter for what’s, right now, one thing of a uncommon sight: a basic tape punch machine.
“The converter venture is meant for the Facit Kind 4070 Code 0001 Paper Tape Punch. This early 4070 relies on 6V DTL [Diode-Transistor Logic] logic and solely has a parallel interface,” Kraan explains of the venture. “By interfacing an Arduino Nano [compatible microcontroller] to the parallel connector (with correct degree conversion) a serial interface is added. The board is powered by the 4070.”
An Arduino Nano-compatible microcontroller drives this DTL parallel to RS232 serial adapter for a classic Facit 4070 tape punch. (📷: Fred Jan Kraan)
Launched within the late Nineteen Sixties, the Facit 4070 was designed because the write portion of a paper tape read-write system — designed for improved portability and, arguably, reliability than the punch-card system that had preceded it, itself impressed by the operation of the programmable Jacquard loom. Applications have been punched as holes right into a roll of paper tape, which might then be learn again by a tape reader sometimes linked to a TeleType terminal.
As you would possibly anticipate from a bit of Nineteen Sixties know-how, although, the Facit 4070 would not include a helpful USB port — and even its native knowledge connection is an indication of the instances, being a parallel port utilizing the elevated voltage of a Diode-Transistor Logic (DTL) system reasonably than the Transistor-Transistor Logic (TTL) frequent right now. That is the place Kraan’s adapter is available in: changing that parallel DTL interface into an RS232 serial connection.
The tape punch is in glorious situation, and with its new serial port adapter ought to begin storing knowledge once more. (📷: Fred Jan Kraan)
“The project-board interfaces all indicators of the 4070, however solely a small subset is used within the first firmware,” Kraan explains. “Information can solely transferred at 600 Baud, which is slower than the 4070 punch velocity. This implies no handshake must be carried out. The Arduino console is just used for testing, however can doubtlessly (additionally) be used for knowledge switch.”
Supply code and KiCad design information for the venture, which have been lately up to date to work round just a few errata within the unique launch, can be found on Hackaday.io underneath an unspecified license.
