3 Aug
2026
3 Aug
'26
10:41 a.m.
On Aug 3, 2026, at 1:59 PM, Len Shustek via cctalk
<cctalk(a)classiccmp.org> wrote:
At Sat, 1 Aug 2026 20:42:23 -0400, David Gesswein <djg(a)pdp8online.com> wrote:
Clearly, yes. One problem is that you'd need a suitable tape head. All the rest is
just software.
Did you use one of those high track count MR heads that some others have used, so you can
deal with funny track counts? I know of some 1/2 inch tape with 10 tracks (Electrologica
X1).
paul
The reader is a bunch of instrument amps that
amplify to levels usable by
Saleae logic 16 pro which has analog digitization mode and way too many
times repurposed code to decode it. Doesn't look like I have put it online
probably because the code is embarrassing but ok with giving it away if
someone has use for it.
Here's an alternative to consider: Years ago I wrote a program to decode
waveforms digitized from cruddy old mag tapes in various formats,
including 7-track NRZI, 9-track NRZI, PE, and GCR, and 6-track Whirlwind.
https://github.com/LenShustek/readtape
We've read hundreds of tapes, mostly digitized using a Saleae analyzer.
I never wrote a DECtape decoder, but it would be doable.