CDT to real tape on CPC?

[mr_lou]

I would like to write CDT files onto real tapes using my CPC464.
Is there any CPC program that lets me do this?
I'd first copy the CDT file onto a disk, which of course means it shouldn't use more than 178kb, which I'm also assuming most CDT files doesn't.

[arnoldemu]

I would like to write CDT files onto real tapes using my CPC464.
Is there any CPC program that lets me do this?
I'd first copy the CDT file onto a disk, which of course means it shouldn't use more than 178kb, which I'm also assuming most CDT files doesn't.

Sorry, I don't know of any program that will do that on the cpc. CDTs vary in size, but mostly it's compilations that could exceed 178k.

It can be done on the pc.

[mr_lou]

bummer.....

I was chatting with doz on channel #crtc on irc.t4nk.org. He said:

if they're "normal" format files, you could just use the standard headerless CAS_WRITE function
this is used for the header and data of each normal file block
if you're wanting to write speedlock tapes out, you're probably out of luck because they're written to pretty exact timings and so it'd be hard to write a generic program to create them

So, would it be relative simple to write a program that writes CDT files to a real tape?

[TotO]

What's the interest to get CDT files if you can't restore them on a real tape ?
Enjoying boring loadings instead of playing with DSK ?

I have though that can be used for the posterity...

[mr_lou]

I agree it makes no sense if CDT files can't be restored back to a real tape.
Surely that's possible. And if it is, then why shouldn't the CPC be able to do it?

[Cholo]

...
Enjoying boring loadings instead of playing with DSK ?
...

Well, boring loading is part of the fun of cause. Also loading tapes can be quite different from their disc versions .. from small things like blinking pixels between blocks (loading screens with stars in the sky or corals blinking in the deep) or reverse/incremental/fading/colour screen schemes, animated counters, flashing borders, multiple screens and most importently the firebird music loaders 

Of cause then there is all the "bad" stuff to experience as well. From the unintentional read errors to the "intentional" ones like original tapes with read errors from the factory and lenghty loading times.

I agree it makes no sense if CDT files can't be restored back to a real tape.
Surely that's possible. And if it is, then why shouldn't the CPC be able to do it?

No doubt a program running on a CPC should be able to extract the data from a CDT and save it back to tape .. at least in theory with normal amstrad blocks etc. Probably to complex to do one that supports all the protected loading schemes as well.

Anyways, what most people probably do to get a CDT back to tape is convert it to WAV on pc and then play it back to a tape recorder. The big "secret" about converting CDT (both ways) is to know that CDT are basicly the same as a spectrum TZX .. and there is a LOT of TZX conversion software.

I suggest using the excellent spectrum TAPIR 1.0 program for quick conversion (Windows compatible):
TZX and Tapir homepage

Like:
1. rename filename.cdt to filename.tzx
2. Open the file in Tapir.
3. Choose "Play to WAV"
.. and you get to choose a filename etc. Tapir is pretty good for converting (both ways) as it know most of the protections as well. Oh, and there are lots of other similar tools out (like playtzx etc) but do note that most of em are really old so probably need to run in "dosbox" or similar enviroment to be used.

Another way of getting a audio output is to play the tape back in a pc emulator (like CAT the tape) and then record the audio externally using the jack-out/speakers plug.

How you use the WAV or other audio source is up to you .. either recording it to tape first or use one of those car-adapters direct in your 464. The car-adapters usually do work with 464 but i should warn you that you should probably choose the most basic ones with wires. Technology actually limits our options here .. as the more advanced adapters and players has all kinda "noice reduction" or "equalizers" that will disturb the output signal .. so the more cheap, old and basic the better. Like you might try to convert the WAV to a audio CD-R and play it back in a cd-walkman .. but if the cd-walkman isnt ancient, itll probably automaticly "help" the signal beyond recognizable. Ive tried those fansy wireless cassette SD adapters and totally failed .. all really cool that you can just chuck a audio file on a SD card and put it in the adaper and it play back wirelessly in the 464 .. but they only accept MP3 and also has permanent equalizers on = useless.

What ever you do i can promise you that youll probably get into troubles (read errors/volume and other audio troubles) but it IS possible .. even with most of the protected games. Oh, and dont forget to use "normal position" tapes as those "metal" tapes arnt good for data storage.

[mr_lou]

Anyways, what most people probably do to get a CDT back to tape is convert it to WAV on pc and then play it back to a tape recorder.

I don't want to use that method.

What ever you do i can promise you that youll probably get into troubles (read errors/volume and other audio troubles)

And that's exactly why.

[Gryzor]

What's the interest to get CDT files if you can't restore them on a real tape ?
Enjoying boring loadings instead of playing with DSK ?

I have though that can be used for the posterity...

Actually I enjoy loading games from tape whenever I get a chance to get my 464 out. It's all about the feeling. Plus, the loading sound stays with you forever...

[arnoldemu]

I don't want to use that method.

And that's exactly why.

Writing the cdt on the cpc requires exact timing. It's not impossible but difficult. I guess decoding the cdt, converting it into the z80 code needed to write it out, or some kind of generic way to write the databits with the correct timing.

For standard headerless or block loaders this is much easier because you can call the firmware to do the whole block. Of course the tool on the cpc would need to be able to detect that it can do this.

No I don't have time to make the tool.