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Add MMC3 auto detect

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sanni 2022-10-06 19:58:04 +02:00
parent 1a8d127011
commit b7fa65a3de
1 changed files with 19 additions and 2 deletions
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21
Cart_Reader/NES.ino
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@ -457,7 +457,7 @@ boolean getMapping() {
println_Msg(F("Searching database"));
display_Update();
// Read first 512 bytes of prg rom
// Read first 512 bytes of PRG ROM
for (int x = 0; x < 512; x++) {
sdBuffer[x] = read_prg_byte(0x8000 + x);
}
@ -472,8 +472,25 @@ boolean getMapping() {
char iNES_STR[33];
sprintf(crcStr, "%08lX", ~oldcrc32);
//MMC3 maps the last 8KB block of PRG ROM to 0xE000 while 0x8000 can contain random data after bootup
char crcStrMMC3[9];
// Read first 512 bytes of last block of PRG ROM
for (int x = 0; x < 512; x++) {
sdBuffer[x] = read_prg_byte(0xE000 + x);
}
// Calculate CRC32
oldcrc32 = 0xFFFFFFFF;
for (int c = 0; c < 512; c++) {
oldcrc32 = updateCRC(sdBuffer[c], oldcrc32);
}
sprintf(crcStrMMC3, "%08lX", ~oldcrc32);
print_Msg(F("for "));
print_Msg(crcStr);
if (strcmp(crcStrMMC3, crcStr) != 0) {
print_Msg(F(" or "));
print_Msg(crcStrMMC3);
}
println_Msg(F("..."));
display_Update();
@ -532,7 +549,7 @@ boolean getMapping() {
skip_line(&myFile);
//if checksum search successful set mapper and end search
if (strcmp(crc_search, crcStr) == 0) {
if ((strcmp(crc_search, crcStr) == 0) || (strcmp(crc_search, crcStrMMC3) == 0)) {
// Rewind to start of entry
for (byte count_newline = 0; count_newline < 4; count_newline++) {