Two questions on C64 emulation

[chip]

Hi guys

Sometimes i use to emulate also the C64 ..... just for fun

Anyway i have two technical questions about C64 world

I have some PRGs which contains cracked games

There's a way (a tool ?) to extract the cracktro from the file PRG ?

I have also some games on D64s files, which actually are just PRGs on the disk

Again, there's a (Windows) tool to extract the PRGs from D64 files ?

Thanks in advance, chip

[drHirudo]

VICE has all the tools you need.

For extracting files from D64 on Amiga you can use http://aminet.net/disk/misc/d64_fs.lha
D64 file system.
Or UnD64
http://aminet.net/misc/emu/und64.lha

[chip]

Thanks, i have WinVICE

Which exactly are the tools you are referring to ?

[drHirudo]

In WinVICE:

bin/c1541

[chip]

Thanks again ..... i see

Question is mandatory :

what syntax i must use to extract the cracktro from PRG file .... is that possible ?

[phx]

Originally Posted by chip

what syntax i must use to extract the cracktro from PRG file .... is that possible ?

When you have the PRG file on your local disk you will use a 6502 disassembler and your own 6502 skills to extract it.

[chip]

Ahhh, so that's really easy

Seriously, there's no tool to do that ?

[jayminer]

No, there's no tool for that. How would a tool be able to know what code is a cracktro and what code is the actual game? The only ways I can think of to get rid of a cracktro is to either find a version without a cracktro, remove it yourself with a machine code monitor or you could simulate a cartridge with freezer functionality and freeze and then dump the memory just after you've skipped the cracktro.

[StatMat]

As others have said, it isn't really possible to automagically remove intros and such. The best way is using the machine code monitor in an emulator to find the games actual entry point after the intros and such have been displayed and dumping at that point. And of course freezers can be used, but this is just plain ugly imho.

Having said that, sometimes the unp64 tool can be used for this purpose (http://iancoog.altervista.org/C/unp64_236.7z). But you still have to know what to do with the resulting unpacked PRGs (i.e. add a boot routine etc).

However, it should be noted that distributing games extracted from scene releases is quite rightly frowned upon. This is why I created the OneLoad64 Games Collection, which now has over 1000 quick-booting games in Magic Desk CRT format which have been dumped from images of the original media (i.e. the process does not involve removing intros from scene releases). There's a thread on this forum [here] about the collection. Should be a lot easier than trying to do it yourself.

And for working with D64s under Windows (i.e. extracting PRGs and such), you can't go far wrong with the excellent [DirMaster].

[chip]

Ok guys, thanks for the replies

No, i am not going to learn machine code for C64 ..... it was just for curiosity