On 8/5/2021 2:57 PM, Len Shustek via cctalk wrote:
> On Aug 5, 2021, at 8:39 AM, Jay Jaeger via cctech
<[email protected]> 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
Cool!
For completeness, here is a link to Paul's 7 track recovery software
info (which is what I believe you are referring to - there is also an
older version.)
http://piercefuller.com/collect/a7tv.html
As a one-time physics major, I *am* interested in the Schoonschip
content. I've offered to James Liu to give it a go if he can't get
someone like Chuck to read it in a more straightforward fashion.
There is also this one for 9 track drives:
https://github.com/jakubfi/ninetracklab
(There is an article out on the 'net that points to this project,
referencing use of a logic analyzer to capture the data, but today I am
having trouble finding it with my searching spells.)
JRJ
