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lbaeza

Cassette copier question

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Hi

 

Last night I was converting from cassette to disk format some of my old programs for the Atari.

Amongst these programs I found this one, a cassete program copier:

 

casscopy1.bmp

 

This programs does it's thing very well, but the thing that has intrigued me for years is that it's a BASIC program (you have to CLOAD it), but the listing is encrypted! Check it out:

 

casscopy2.bmp

 

How can this be acomplished? It's really odd!

 

Regards

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If I remember right, this protection is a one way protection, so you can´t decrypt it. This cryption was done with a poke before saving the programme. It was described in the German book "Peeks und Pokes" by Data Becker.

 

Here some info about the book in German language: ABBUC Infothek

 

If you´re interested in the article about this protection, I coul´d scan it and send it to you.

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I think that in the program file there is entered some junk instead of real variable names. I also remember there was some program (or maybe pack of programs) that allowed you to rebuild those variables, but i just don't remember its name at the moment...

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Yes, I remember this "protection" and we made a small program to undecrypt it. I'll search in my old cassettes, but I doubt it's going to be an easy task.

 

stay tuned for new info :D

 

devwebcl

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Well,

simply e-mail me and I will return a zipped ATR image with the Repair Station, as well as other Basic listing deprotectors...

 

Besides, I have found some other kind of Basic listing protection: Normally a Basic screen has space for 38-40 chars. Some of my Basic programs appear to have only 20 chars (or less) per line. You can list them without any problem (though some of the lines are empty and there are more than 3 lines quite often). BUT, you cannot edit these programs in any way, meaning you cannot change them. I tried a Poke 82,x and Poke 83,x but this did not help, the program still listed with 20 (or less) chars per line. whenever I tried to edit (change) a certain line an Error occured. So, whats that kind of protection ?!? How can one remove it ?!?

 

None of the Basic listing deprotectors I have could remove or alterr this kind of protection... -Andreas.

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One of the very first programs I wrote for the A8 was a basic program to copy boot tapes.

It simply opened the cassette port for reading, then read as many bytes that would fit in RAM with Basic on into a string. Saving it was the reverse process. It was so simple, I didn't expect it to work but it did, as long as the boot tape programs were shorter than the available memory. The most time into the program went into figuring out the very maximum size of the string, by trial and error :):)

 

It had one disadvantage: it added extra End of program blocks at the end of the tape but that didn't hurt the function of the program :)

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I think that in the program file there is entered some junk instead of real variable names. I also remember there was some program (or maybe pack of programs) that allowed you to rebuild those variables, but i just don't remember its name at the moment...

I wrote a SALVAGE program to restore BASIC variable names. It doesn't restore the original name, just restores to

a usable name, so the program can be Listed. Jindroush also wrote one, I can't remember its' name right now.

My program uses a SAVEd BASIC file and converts it to a LIST file. My programs are Atari BASIC programs,

Jindroush's program is a MSDOS file.

 

edit: His name is Jindrich Kubec, his DOS program is chkbas.exe. He also has a DUMP .ATR for Atari

salvage.zip

Edited by russg

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Finally, I can see the list. Thank you!

 

Any idea about modifying this copier for use it with bigger games? Ex: Zybex

 

copye.png

 

 

Yes, I was thinking (hoping) about more memory also. The program can convert single and multi-stage tape programs to disk easily. In some ways (or circumstances) its better than Howfen Tape to Disk or Transdisk or other Cass.-Simulator programs. Alas, it is so damned limited to approx. 36kbytes... (and a max. of 8 files/stages, which is not a big problem with most tapes, since only a few tapes have more than 8 stages).

 

If I remember correctly I have several versions of this program in my collection, with small differences each (not only text differences). It would be great if someone could patch+enhance the program to support the 64k XRAM of a 128k machine, so that we end up with 36k + 64k = 100k total. (Think it is the tape copier-program that is limited to approx. 36kbytes, not sure if the bootcode or boot-program it writes to the diskette [together with the copied tape-data] is also limited to load programs with a max. length of 36k.)

 

I used this program successfully to copy games from tape to disk on a number of programs that failed with Howfen tape to disk (meaning they could be copied from tape to disk with the Howfen program but did not work afterwards, while they could be copied from tape to disk with this program and worked fine afterwards). The program can also transfer boottapes to disk that are normally booted with the Start key only (since they require Basic enabled) and these programs work fine from disk (which they do not with the Howfen program)...

 

Since Howfen Tape to Disk fails with most (all?) compiled Basic programs, like e.g. some programs by Microprose and SSI, maybe this program would convert and load them successfully - if there were more memory available (and not only 36k)...?!?

 

Attached is one of the versions I have, maybe you can also upload your version...

mtap2disk.zip

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Any idea about modifying this copier for use it with bigger games? Ex: Zybex

 

copye.png

 

Some time ago, vitoco and dogdark developed something very interesting: DOGCOPY.

It allows copies from any source to any destination. (16k-208k!!)

 

...evolucionó para soportar más de 4 bancos de 16K, permitiendo grabar desde 1 hasta 17 bancos dependiendo del tipo de expansión de memoria reconocido entre 130XE, 800XL con Buchholz, Rambo/XL, Rambo320K, Newell, Newell modificado e incluso ninguna. Esto es, desde 16K hasta 208K!!!

sitvit.png

I think we can use this to make the improvements...

dogcopyv1.rar

Edited by suppawer

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