Recovering data tapes the hard way: CROOK OS

The awesome folks over at Hackaday (sponsors of VCF East) linked to a great article by a collection of Polish computer archivists and museums. One of them was working on an emulator for the Polish MERA-400 computer – but the only known copy of the machine’s OS was locked on 9-track tapes.

The CROOK operating system was supposedly stored on 5 magnetic tapes at the Warsaw Museum of Technology, so they had to find a way to read it. Luckily, the museum had done an excellent job of storing and preserving the tapes. Unluckily, their IBM 9438 tape drive didn’t like the encoding of the tapes’ header. The museum also had a Qualstar 1052 in their possession, but none of the necessary interface hardware. So, out came the Arduino and the logic analyzer.

Eventually, the team had to resort to sampling the flux transitions directly from the tape head electronics and decoding the resulting data into bits. The result was “Nine Track Lab”, a python suite for decoding 9-track tapes written in any density and in any writing standard.


Nine Track Lab: GitHub
Via: Hackaday

Author: Josh

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