5 Aug
2021
5 Aug
'21
1:12 p.m.
On Aug 5, 2021, at 3:57 PM, Len Shustek via cctalk
<cctalk at classiccmp.org> wrote:
I remember reading that -- nice piece of work indeed. Around the same time I also saw a
project along the same lines in Poland, which recovered an interesting body of software
for various early Polish machines.
One of these days we hope to read some 10-track 1/2 inch tapes from an Electrologica X1, a
very odd format that could be described as "DECtape with variable length
blocks".
paul
On Aug 5, 2021, at 8:39 AM, Jay Jaeger via cctech
<cctech at classiccmp.org> wrote:
I know Paul well (we were contemporaries at U. WI). He does not do that very often. He
did not indicate any issue with a fire at the building that contains his collection when I
last spoke with him.
He does not actually read "blocks". He reads the tape in an *analog* fashion,
and then processes the results with software. That is how he recovered the IBM 1410
system tapes and diagnostics, for example.
To be honest, I doubt that this content would be such that he would be likely to
volunteer.
Some years ago, inspired by Paul Pierce's earlier program in Java, I wrote similar
software in C to decode the analog waveforms from tapes in a variety of formats: 7-track
NRZI, 9-track NRZI, PE, and 6250 BPI GCR, and 6-track NRZI for Whirlwind.
https://github.com/LenShustek/readtape