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Merge pull request #120 from cayce-msx/115_enable_SCC_detection

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support SCC-I enable/disable in slot with ROM
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LibretroAdmin authored and GitHub committed 2023-04-17 23:04:26 +02:00
2 parents f97252b233 39458029ce
commit 1806eed437
1 file changed
+9 -4
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fMSX/MSX.c
+9 -4
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@@ -1480,8 +1480,10 @@ void MapROM(uint16_t A,uint8_t V)
/* Only interested in writes to 4000h-BFFFh */
if((A<0x4000)||(A>0xBFFF)) break;
J=(A-0x4000)>>13;
/* Turn SCC on/off on writes to 8000h-9FFFh */
if(J==2 && I<2) SCCOn[I]=(V&0x3F)==0x3F;
/* Turn SCC on/off on writes to 9000-97FF */
if(J==2 && I<2 && (A&0x1800)==0x1000) SCCOn[I]=(V&0x3F)==0x3F;
/* Turn SCC-I on/off on writes to B000-B7FF */
else if(J==3 && I<2 && (A&0x1800)==0x1000) SCCOn[I]=(V&0x80);
/* Switch ROM pages */
V&=ROMMask[I];
if(V!=ROMMapper[I][J])
@@ -1510,8 +1512,11 @@ void MapROM(uint16_t A,uint8_t V)
/* Only interested in writes to 5000h/7000h/9000h/B000h */
if((A<0x5000)||(A>0xB000)||((A&0x1FFF)!=0x1000)) break;
J=(A-0x5000)>>13;
/* Turn SCC on/off on writes to 9000h */
if(J==2 && I<2) SCCOn[I]=(V&0x3F)==0x3F;
/* Turn SCC on/off on writes to 9000-97FF */
/* note that the 'if' above already filtered anything but 9000. That ignores the mirrors - see https://www.msx.org/wiki/MegaROM_Mappers#Konami.27s_MegaROMs_with_SCC */
if(J==2 && I<2 && (A&0x1800)==0x1000) SCCOn[I]=(V&0x3F)==0x3F;
/* Turn SCC-I on/off on writes to B000-B7FF */
else if(J==3 && I<2 && (A&0x1800)==0x1000) SCCOn[I]=(V&0x80);
/* Switch ROM pages */
V&=ROMMask[I];
if(V!=ROMMapper[I][J])