I'm looking for the exact tape data format of old SVI-318/328 computers, some kind of whitepapers explaining it.
I've obtained several information from a real tape, but I don't known if the infered rules are correct, if exists any variants, the correct bauds...
Empirically taken from a WAV file the format is:
The bits are codified like this:
- 0: 4 pulses at ~2400 Hz
- 1: 4 pulses at ~4800 Hz
Each data block have a pilot tone followed by the data without a pause between them.
The pilot can be codified like 199 bytes with value 0xAA + 1 byte with value 0xFF. These bytes don't have leading or trailing bits and are in MSb format.
And data come codified not using leading bits, and one 0 valued trailing bit. They are also using MSb.
What I need is a confirmation of this coding or not in case there is something missing or not accurate.