TI99 OLD CS1 problem

[HOME AUTOMATION]

4 hours ago, mike_z said:

In fact with the volume up all the way, I have to turn off the speakers.

If you've fed too much juice into the TI, you could have blown out R406, U400. The intended type of player, probably puts out <1 watt.

[Tursi]

On 11/30/2021 at 3:36 PM, mike_z said:

The response is 'NO DATA FOUND'. I know that there is a good leader tone.
...
DO you know what bit pattern is used for the leader? I could easily see that, because it is repeating and last rather long. Mike

I know logic analyzers don't tell you the voltage, but they usually allow you to configure the threshold voltage, you can use that config to work it out.

 

You hearing the tone is not the same as the TI hearing the tone. You have an incredibly sensitive and high resolution audio sensing device, even buried in noise. Your TI has a transistor and a capacitor. It doesn't even know what a tone is - it's just timing phase changes.

 

You're going to have a hard time reading characters out of the data stream - it's not an avenue I'd even spend time on trying to do. Your logic analyzer will NOT know the encoding - it's proprietary. Even if you do manage to decode the wave file, what have you proven? If you just want to prove the audio file is valid - load it into one of the conversion tools, one of the supported emulators, or post a copy for us to test for you.

 

The leader tone is 768 '0' bytes. This sets up the timing for the read routine - a 1 bit is indicated by changing phase in the middle of a single time period. You can read about the encoding and the data format here: http://www.unige.ch/medecine/nouspikel/ti99/cassette.htm

 

[DavidC]

When you connect the tape recorder to the computer,  and you type OLD CS1 and follow the prompts, press play and all that...do you hear the noises thru your tv/monitor speakers? 

[+Schmitzi]

 

"OLD CS1" problems ? ?

 

 

@OLD CS1 hates this trick ?  ?