[FPGA64] Strange .prg bug

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DanyPPC
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[FPGA64] Strange .prg bug

Postby DanyPPC » Tue Dec 18, 2018 9:33 pm

As told in other topic I tested a lot of prg files and I noticed that someones didn't start as due. So, for example, I took Arkanoid TCS Crack. If I load the D64 the game starts and works properly. If I extract (Using DirMaster) the prg file of this disk and load it with "PRG-Load" option and then digit RUN + Return the game doesn't start.

So I have made antoher test: Backupped the Arkanoid TCS Crack just at the start with my Ultimate II cartridge (Freeze function) on real C64 hardware, saved the prg into a D64 file and extracted it always with DirMaster on Windows.
So the prg file ripped with the cartridge works ok on MiST C64 fpga core.

I have made this procedure for other prg games that didn't start on MiST.

There is something that does not work as it should when you load the individual prg files in place of the same in D64 format.

In order I have downloaded various Arkanoid in prg format and only one has started on MiST while these work well on VICE.
I spent a lot of time to replace those prg files that do not work on MiST with others that start instead, and in some cases I used the freeze function of the Ultimate II to have compatible files starting on the MiST.

So, for information. Thanks for your attention.
If someone wants to share his experience on this, he is welcome.

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MasterOfGizmo
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Re: [FPGA64] Strange .prg bug

Postby MasterOfGizmo » Fri Dec 21, 2018 7:28 am

Prg loading is a nasty hack and the core does some magic fiddling in memory that a regular c64 would do itself while loading. It may very well be the case that this doesn't work properly with all games.
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DanyPPC
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Re: [FPGA64] Strange .prg bug

Postby DanyPPC » Fri Dec 21, 2018 7:42 am

Ok, many thanks MasterOfGizmo for the clarification.


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