SOS - Reviving a Power 3000 tape

[andejens]

Hello,

I have found quite a few old tapes. Some of them are Power 3000 tapes. Question - will the EightyOne emulator be capable of running the Power 3000 games? Running the Lambda 8300 hardware. Or do you need a different emulator?

I have a recording of one of the games here. The game is called SOS
https://www.dropbox.com/s/1ppmtb3fyh0gm ... W.wav?dl=0
https://www.dropbox.com/s/pduwr4slifvex ... W.wav?dl=0
I have recorded both sides of the tape just to be sure.

I have attempted digitising the tape with a utility one of my friends has made:
https://github.com/mvindahl/zx81-dat-tape-reader
But it has been unsuccessful as it ends up with different results for both sides. (It has proven quite easy to use in other cases)

I would appreciate if a kind soul could assist me - and share the method that results in a succesfull file that can load into an emulator (if any)

All the best

Anders

[XavSnap]

Hi Anders,

spectape.JPG (109.45 KiB) Viewed 30157 times

Try to load the wav file in "ZxSpectape", select all, reverse the signal and run the "auto-symmetry" filter.
Save it in another wav file...

And try again on your favourite emulator.
Have fun!

[XavSnap]

Hi !

NewRawBloc_Side1.P

(1.89 KiB) Downloaded 635 times

NewRawBloc_Side2.P

(1.89 KiB) Downloaded 675 times

But something wrong on the second side:

zxsectape2.JPG (111.28 KiB) Viewed 30158 times

[mrtinb]

Loading it into JSZeddy shows that side 1 is corrupted as well.

Line 14 is the first line.

lambdaside1.png (6.69 KiB) Viewed 30144 times

[mrtinb]

Looking at the recoding in Java ZX81 Tape Converter it looks beautiful.

Looking at the description of the file format of Lambda 8300 it seems Lambda files should start with $FF where ZX81 files start with $00. Maybe some WAV -> P utilities will corrupt the file by setting a $00. Seems there's no file format for Lambda 8300, so WAV is probably the best way.

Unfortunately my installation of Eighty One won't emulate Lambda 8300 at the moment. The great thing about Eighty One is that it supports WAV files.

[XavSnap]

Hi all,

Yes, this tape is corrupt...
It miss 4 signals... in the D_file :

Code: Select all

Offset      0  1  2  3  4  5  6  7   8  9 10 11 12 13 14 15
00000608   00 00 00 76 00 00 00 00  00 00 00 00 00 00 00 00   ...v............
00000624   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
00000640   00 00 00 00 76 00 00 00  00 00 00 00 00 00 00 00   ....v...........
00000656   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
00000672   00 00 00 00 00 76 00 00  00 00 00 00 00 00 00 00   .....v..........
00000688   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
00000704   00 00 00 00 00 07 60 00  00 00 00 00 00 00 00 00   ......`.........
00000720   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
00000736   00 00 00 00 00 00 07 60  00 00 00 00 00 00 00 00   .......`........
00000752   00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
00000768   00 00 00 00 00 00 00 07  60 00 00 00 00 00 00 00   ........`.......
00000784   00                                                 .

I had to shift 4 bits to the right to decay the "07 60" code to "00 76"

The right file "????" is ...

New_S.p

(1.89 KiB) Downloaded 643 times

But, it seem to be corrupt too...


To launch the Lambda EO emulation, you had to select:
[16 K ram.]
[Protect ROM from write.]
[NTSC TV.]
All other captions must be unselected...

[andejens]

Hi Jesper and XavSnap,

Thanks a lot for your assistance so far. I wonder if it would be possible to patch a version of the tape - using the best bits from each recording?
I guess this is the idea with the "Java ZX81 Tape Converter" tool - but I never quite got the idea.

Noob question: How do you see that the tape is corrupt? The example from side 2 is pretty obvious as there suddenly are 5 pulses instead of 4.
XavSnap - in your example above - how do you detect that 4 signals are missing?

[XavSnap]

Same problem regard the second side...

New_S2.P

(1.89 KiB) Downloaded 655 times

A REM line can be displayed...
Perhaps it may be retrieve using the side 1 end part.

best bits from each recording?

I tried to retrieve "The tube", the first part is too loud and corrupt, the second one seem ok, but... don't work!

[mrtinb]

Yes, this tape is corrupt...
It miss 4 signals... in the D_file :

You are aware the D-file is positioned differently on Lambda 8300?

[XavSnap]

Hi Martin,

Yes, of course...
The D_file is the same regard the ZX81 one... but "00 00 76 00 ... 00 07 60 00" is incorrect!
I ever seen this problem on other tapes... and it's not a bad tape sound !

Just use another soft recorder.
Some of them had to corrupt the recorded file, due to a bad software buffer!
It trim the WAV file and delete some datas in the target wav file...

I ever seen it on Apple sound recorder!
The tape isn't corrupt, but the wav file seem to be cut and create a bad signal.

The tape: "WWW_W_W_WW!W_WWW_W!WW_W_W_WWW"
The numeric recorder: "WWW_W_W_WW!WW_W_W_WWW"
You lost the "W_WWW_W" part, how create a decay on the emulator (bits lost)

Is our case, "_WW_WW_WW_WW_" had been lost in the D_file! (4bits lost in the datas!)

I don't know if it's due to the encoder, the MPG1_L2, or the resolution converter... using a memory cluster of data...
But, some of datas seem to be deleted in this target wav file... and all other files, recorded by this numeric recorder!
I suggest to use another tool (software) to get the dump... this one seem bugged!

Andejens, try to record it using another computer or get another software, and try again in EO.
.... Or use the raw sound file...without conversion!
The tape reader is not corrupt, ... it simply a numeric failure due to your software.

The best way to dump datas, is to load the tape sound directly on the emulator, without numeric recording...


Maybe the same problem on "The tube" !

Have fun...