Help reading a 9 track tape
aek at bitsavers.org
Fri Aug 6 12:01:46 CDT 2021
On 8/6/21 9:45 AM, Len via cctalk wrote:
>> 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.
The advantage of digitizing the output of the head preamp with a https://usd.saleae.com/products/saleae-logic-pro-16 is you can do software
AGC and sometimes do eyeball recovery of dropouts.
Disadvantage is for a long tape you need >128gb of RAM as a capture buffer, and even with lossless compression the captured data files
are quite large. The Saleae is also pretty expensive, but work really well.
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