[FR] External audio input for loading real tapes

[lroby74]

Hello,
would be possible to add real tapes loading via a tape recorder and using external audio jack input?

Thanks in advance

Best Regards
Roberto from Italy

[Speccery]

Hi Roberto,
Good request. Would be interesting to check it out. The timing would be the obvious challenge, I need to check how the original TI-99/4A handles tape loading. I seem to remember that it would be timed with the hardware timer built into the TMS9901. If that is true, then implementing the tape loading would be a lot more feasible. If the timing is based on software, it would be much harder as the CPU is running so much faster and with different timing.

[lroby74]

Hello again,
i've just discovered that all TI994A tape games are on WAV format, so would be enough to enable WAV reader from external audio input (IMHO!) to solve problem?

[nippur72]

this page has some details on the cassette tape interface: http://www.unige.ch/medecine/nouspikel/ti99/cassette.htm

According to it, timings are done via the TMS9901, so in theory it's a matter of connecting the CRU bits 25 and 27 to the audio input and output bits. I guess the motor can be simply ignored.

Anyway when I do a SAVE CS1 (gyurco's fork for the Mist board) it gets stuck on the * RECORDING phase, never completing it. Perhaps there's something missing with the timings?