Is this a ZX81 recording or not?

Discussion about ZX80 / ZX81 Software
Fruitcake
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Re: Is this a ZX81 recording or not?

Post by Fruitcake »

XavSnap wrote: Tue Aug 04, 2020 5:29 am Seem corrupt…
TAPE VERIFY.P
Here's the assembly listing for machine code of the Tape Verify program. It appears to be fine with no sign of corruption:
TapeVerify.asm
(3.12 KiB) Downloaded 77 times
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XavSnap
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Re: Is this a ZX81 recording or not?

Post by XavSnap »

Thanks Paul.
Still worth re-recording...
Yes it was badly corrupt.
About five mute or bit decay.
The Basic program can be rebuilt using "ZxToken" P to TXT, but the main part of this game is in the Vars values.
I ever type-ins the "little pocket book for the Zx81" and the adventure game "La maison du Dr. Folibus" , the basic program was the same…
But, we had to retrieve the VARs bloc…

I had to check all lines header values, the system variables, the VARs structure and many bits errors " 1C" was "6C"...
And finish the debugging with the GOTO command in the basic editor.
It was a fastidious work…

Luckily the program did not contain a machine code routine that we should have disassembled.
:mrgreen:
Last edited by XavSnap on Sun Aug 09, 2020 9:58 pm, edited 1 time in total.
Xavier
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XavSnap
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Re: Is this a ZX81 recording or not?

Post by XavSnap »

Zip update:
"Tape verify", "Cauchemard House".
CompilWill.zip
(132.24 KiB) Downloaded 59 times
(minor changes on "Cauchemard-House")
Xavier
willinliv
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Re: Is this a ZX81 recording or not?

Post by willinliv »

Fruitcake wrote: Sun Aug 09, 2020 11:07 am

Still worth re-recording it and posting it here as might be possible, and maybe try a different cassette player. It might be better than before and might allow some information to be recovered.
Hi Fruitcake, sorry for the absence. When I re-recorded it at a lower volume I kind of lost my temper with this tape because it always to my ears sounded really muddy in noise. Link to the quieter recordings below though. I had tried to adjust the Azimuth screw but I think it's just noise baked in. I do have a second tape player which I have avoided so far because the rollers look really mucky.

I'll try to dig out the actual tape to take a pic of the label too.

https://drive.google.com/drive/folders/ ... sp=sharing
Fruitcake
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Re: Is this a ZX81 recording or not?

Post by Fruitcake »

willinliv wrote: Mon Aug 17, 2020 8:31 pm Link to the quieter recordings below though.
Thanks.

willinliv wrote: Mon Aug 17, 2020 8:31 pm I'll try to dig out the actual tape to take a pic of the label too.
Are these recordings all from this tape?
viewtopic.php?p=38772#p38772


tk3 contains R09_0007.wav and R09_0008.wav
tk4 contains R09_0006.wav and R09_0007.wav

Do you know which side of the tape each recording is of?
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XavSnap
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Re: Is this a ZX81 recording or not?

Post by XavSnap »

:oops:

Can't be a tape problem…
Check or replace the wiring device.
It's probably a wrong ground connexion or a short-cut with two electric cables.

We can ear the buzzer tone (50/60hz) in the program sound !
Check the wiring continuity (ground to ground, + to + and gnd to +) from the two sockets.
Clean to both sockets...
Xavier
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1024MAK
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Re: Is this a ZX81 recording or not?

Post by 1024MAK »

Unwanted 50Hz or 60Hz interference often indicates either a cable is picking up mains interference (use good quality screened cables and check that the plugs are clean), a class I device (which should be earthed) is not earthed - check mains earth connections, or there is a failure of a diode in a PSU. Or a capacitor failure if the PSU uses half wave rectification.

Unwanted 100Hz or 120Hz interference is most likely due to a capacitor failure in the PSU.

In both cases, the fault can be in/by anything that is electrically connected to the computer or cassette tape recorder/player.

Mark
willinliv
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Re: Is this a ZX81 recording or not?

Post by willinliv »

1024MAK wrote: Tue Aug 18, 2020 12:52 pm In both cases, the fault can be in/by anything that is electrically connected to the computer or cassette tape recorder/player.
Appolgies to both you and XavSnap. I have been kitting out my new man cave but have got round back to the tape collection. Have got our my second tape player so fingers cross it gives some more usable data.

To come on a couple of the points raised - I realised I got in a bit of a muddle with the recordings, so going to try to be a bit more organised. It looks to me like the tapes of most interest are two tapes: one with a label GMSave (that also featured Breakout on one side); and a second tape which seems to be a collection of compilers on it including MC/GMSave (pictures of both to follow). So I'll concentrate on these because the other stuff is all available online.

Regarding the hum, I think it's in the recording because it isn't there once you stop/pause the tape even with the recording device (a wav recorder) still recording, connected up etc. And it just sounds a much more muddier tape with noise compared to the others I have and have captured using the same setup. Having said that, the lead I am using to interface between tape deck and my recording device is terrible! I made it myself and it goes from 5-pin DIN to mono 3.5mm, so anything is possible! If I could run everything off battery power I bet it would sound better.

I'll give it a go over a couple of nights this week and be right back. Thanks again for your interest and perserverance!

Regards, Will
willinliv
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Re: Is this a ZX81 recording or not?

Post by willinliv »

Hi Xavsnap and Mark,

As you had both hinted, I improved my capture setup. I have improved my audio cable (joining a MIDI and a 3.5mm cable to attach my DIN tape player to my audio recorder in stereo rather than shorting both Left and Right together), and results are now much better. Tapeutils/ZX81 Tape Converter is able to correctly interpret the same and more programs than my previous setup.

So I promised some better recordings of two of the tapes that seemed to reference 'GMSave'...

https://drive.google.com/drive/folders/ ... sp=sharing

Tape 1_GMSave
Side A - 0051
Side B - 0052 (some of the later programs on this side are somewhat readable to me, and start with GMload - listing below - I don't know if you've already got this piece of the puzzle? It looks like he was trying out methods of saving and the last recording was Breakout. I have asked my father but it's a long time ago and he doesn't remember!)

Tape 18_Compilers
Side A - 0047
Side B - 0048


Apologies in advance - they are big files (~70MB), I have left as stereo in case it helped to decypher. There is pictures of each tape, the original recording, and the same recording broken down roughly into shorter .wav files. There are other tapes I have uncovered that may also use these methods so will post here in case of interest.

Best wishes, Will
gmload.PNG
willinliv
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Re: Is this a ZX81 recording or not?

Post by willinliv »

Fruitcake wrote: Mon Jul 27, 2020 8:26 pm
The filename of the program is "GMLOAD " whereas the version on my website is "RLLOAD " (note the space as the last character of both filenames).
GMLOAD.p
Sorry Fruitcake, realised when I looked through thread GMLOAD was already spotted - so probably not added anything to it with above :roll:
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