Re: [hatari-devel] Blitting from TT RAM seems to work on Falcon?

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 08/10/2023 à 20:25, Miro Kropáček a écrit :
> Hi,
>
> I have a game which displays mayhem on CT60 (even with caches off) but 
> works perfectly fine in Hatari. After ruling out the usual suspects 
> (video base pointing to TT RAM, slow DSP, ...) the only thing which 
> remained is the Blitter which  *is* used by the game.
>
> Looking at the code it seems to be even explicitly allowed?
>
> void Blitter_SourceAddr_WriteLong(void)
> {
> if ( Blitter_CheckAccess_Byte() )
> return; /* Ignore access */
>
> if ( ConfigureParams.System.bAddressSpace24 == true )
> BlitterRegs.src_addr = IoMem_ReadLong(REG_SRC_ADDR) & 0x00FFFFFE; /* 
> Normal STF/STE */
> else
> BlitterRegs.src_addr = IoMem_ReadLong(REG_SRC_ADDR) & 0xFFFFFFFE; /* 
> Falcon with extra TT RAM */ <---- Huh?
> }

Hi

i found a reference for this change in commit 
a02aedff2711b80379081abb82832c92aa0637f0 in dec 2014.

There were a lot of changes at this period regarding TT RAM and 32 bit 
addresses, but I really don't remember where this specific change came from.
Didn't the afterburner of ct boards allow to blit from "TT RAM" too 
instead of just plain RAM ? Maybe the error comes from this and I mixed 
things with a normal falcon.


> When changing "0xFFFFFFFE" to "0x00FFFFFE" and running the game again 
> (with TT RAM enabled) ... the game still works ok. :-) Maybe I'm looking 
> at wrong place?

This needs to be changed in Blitter_DestAddr_WriteLong and 
Blitter_SourceAddr_WriteLong, is that what you did ?

Nicolas