TZX file checksums

[Vag]

Hello everyone,
Do you know of a program that can recalculate and update the checksums of a TZX file easily?
Thanks :--)

[SkoolKid]

I think my answer to your question is going to be "No" regardless, but what do you mean by checksums? Do you mean the parity bytes at the end of data blocks?

[Vag]

Hi SkoolKid, thanks for your response :--))

what do you mean by checksums? Do you mean the parity bytes at the end of data blocks?

Exactly :--)
In case you want to hack a TZX file using romhacking techniques (e.g. edit it with a hex editor), you have to recalculate the checksums. If you check "Fast Tape Loader", Speccy doesn't mind and loads the game, but if you want to make a game hack and release it, it's something you have to do.

I think my answer to your question is going to be "No" regardless

Well, I will need to update the checksums of a hack I'm making and I'm about to finish.
I need something like this: UpdateTapChecksums, but not just for TAP files. I'm sure the author was too lazy to support TZX files (as it's me) :--P~
Maybe there's a workaround, like converting the TZX to something else, and then back to TZX (but without any information loss)? If not, I will have to write an "UpdateTzxChecksums" program, but I would like to avoid it if possible (there's no time).

Regards!

[jpnz]

You can use Tapir if you're OK with Windows

[Vag]

Thank you jpnz!
That's the solution, I will try it after some days, when the game is finished :--)

[Lee P]

I think it can be done in ZX Blockeditor too, although I've never used it for that.

[Ralf]

Personally I use Zx Blockeditor:
https://www.alessandrogrussu.it/zx-modules.html

Hacking a few bytes in some random hex editor will make the .tzx unusable. As you noticed the checksums will be wrong.

But Zx Blockeditor knows about checksums and will adjust them when you click "Save".

If you want to hack a game easily, use a .SNA format for testing. It doesn't have any checksums and can be edited with anything.

[Vag]

Hi friends, thank you both!
I will also try Zx Blockeditor :--)

If you want to hack a game easily, use a .SNA format for testing. It doesn't have any checksums and can be edited with anything.

I don't want to hack a game easily :--))))
There had been games that took me months or years to translate!

I prefer image files to snapshot files, because I want to create new language versions of games, as they would have been made originally.