Another mystery .WAV from a tape

Discussion about ZX80 / ZX81 Software
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angus
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Another mystery .WAV from a tape

Post by angus »

Hi guys.

You have been so helpful in the past. I've found what I think is a very early tape of mine, possibly from 1981. I have no idea what the programs stored on it are. They could be something I wrote or could be type ins or even conceivably pirated software. I have had no luck loading them into the Zeddy, or an emulator.

Can someone help?

The first is here

http://homepage.ntlworld.com/n_gulliver/ZX81_1.wav
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PokeMon
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Re: Another mystery .WAV from a tape

Post by PokeMon »

Very poor audio file - bad quality. :?
angus
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Re: Another mystery .WAV from a tape

Post by angus »

I did say it was a 31 year old cassette! Rescued from a dusty attic with the mouse droppings removed...
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PokeMon
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Re: Another mystery .WAV from a tape

Post by PokeMon »

Maybe you try to use an equalizer for better adjusting to the desired frequency levels.
sirmorris
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Re: Another mystery .WAV from a tape

Post by sirmorris »

Hmm, none of the usual tools will load the wav file; I've tried exporting it from audacity in a number of formats but no luck - I'll keep trying, of course..!
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TMAOne
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Re: Another mystery .WAV from a tape

Post by TMAOne »

I took a crack at this too. No luck.

Back in the 80's I made a ZX81 "Scrubber-Dubber" from plans published in a magazine article. It reads a dubious tape, and cleans up and re-digitizes the waveform so that (1) a ZX81 can read it properly, and (2) you can drive a 2nd slave recorder to make a tape copy of that precious program that won't let you SAVE. The 2nd part has not worked until recently when I obtained and used the called-for silver mica capacitor in the slave tape output circuit. (Being a poor student at the time I had tried in vain to find a cheaper workable substitute.) The 1st feature has allowed me to read several unLOAD-able tapes. It has been lent out several times, occasionally requiring threats of violence for it to find its way back home again. It is a golden little device.

Sadly, your .WAV file is in too bad a shape. In a sound editor, the waveform doesn't even look right. There seem to be single peaks and valleys where there are supposed to be groups.

I would suggest adjusting the azimuth of the tape head of whatever recorder you have now. That is the source of 99% of tape incompatibilities. You didn't say, but I'm guessing you're not using the same machine you had 31 years ago. Most have a small Philips screw just beside the tape head, and an opening to let you adjust it. (Sometimes you have to get tricky to get the tape in there with the door still open so you have access, but there is usually a way to do that since this is a factory post-assembly adjustment.

Then adjust the head while you play the tape for the loudest, "brightest" sound. That will mean your equipment is emulating the recorder you had used back then. Make a new .WAV file with that setup, and we can try again.

Ian
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stefano
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Re: Another mystery .WAV from a tape

Post by stefano »

Did not recover it fully but it looks it is a game, named "GALACTIC INVASION".
Does this help you memory ?
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stefano
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Re: Another mystery .WAV from a tape

Post by stefano »

Ok, I'm quite sure your'e trying to recover a copy of this:
"SuperPrograms6(ICL)" http://www.zx81stuff.org.uk/zx81/genera ... (ICL).html
I'd skip the first 6 tracks and look at the end of the tape.
angus
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Re: Another mystery .WAV from a tape

Post by angus »

That makes perfect sense. The tape has my scrawl on it "ZX81 16K G, N, D, J, C, P

Which would be the loading names for each program.
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