use a function to nybblize sector
This commit is contained in:
Brad Grantham
parent
ba52591064
commit
d20991ae8e
166
apple2e.cpp
166
apple2e.cpp
|
|
@ -266,101 +266,107 @@ struct backed_region : region
|
|||
|
||||
const region io_region = {"io", 0xC000, 0x100};
|
||||
|
||||
unsigned char floppy_header[21] = {
|
||||
const unsigned char floppy_sectorHeader[21] = {
|
||||
0xD5, 0xAA, 0x96, 0xFF, 0xFE, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0xDE, 0xAA, 0xFF, 0xFF, 0xFF,
|
||||
0x00, 0x00, 0x00, 0xDE, 0xAA, 0xFF, 0xFF, 0xFF,
|
||||
0xFF, 0xFF, 0xD5, 0xAA, 0xAD };
|
||||
unsigned char floppy_doSector[16] = {
|
||||
const unsigned char floppy_doSector[16] = {
|
||||
0x0, 0x7, 0xE, 0x6, 0xD, 0x5, 0xC, 0x4, 0xB, 0x3, 0xA, 0x2, 0x9, 0x1, 0x8, 0xF };
|
||||
unsigned char floppy_poSector[16] = {
|
||||
const unsigned char floppy_poSector[16] = {
|
||||
0x0, 0x8, 0x1, 0x9, 0x2, 0xA, 0x3, 0xB, 0x4, 0xC, 0x5, 0xD, 0x6, 0xE, 0x7, 0xF };
|
||||
const unsigned char floppy_sectorFooter[48] = {
|
||||
0xDE, 0xAA, 0xEB, 0xFF, 0xEB, 0xFF, 0xFF, 0xFF,
|
||||
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
|
||||
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
|
||||
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
|
||||
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
|
||||
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
|
||||
const unsigned char floppy_6BitsToBytes[0x40] = {
|
||||
0x96, 0x97, 0x9A, 0x9B, 0x9D, 0x9E, 0x9F, 0xA6,
|
||||
0xA7, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB2, 0xB3,
|
||||
0xB4, 0xB5, 0xB6, 0xB7, 0xB9, 0xBA, 0xBB, 0xBC,
|
||||
0xBD, 0xBE, 0xBF, 0xCB, 0xCD, 0xCE, 0xCF, 0xD3,
|
||||
0xD6, 0xD7, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE,
|
||||
0xDF, 0xE5, 0xE6, 0xE7, 0xE9, 0xEA, 0xEB, 0xEC,
|
||||
0xED, 0xEE, 0xEF, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6,
|
||||
0xF7, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF };
|
||||
|
||||
void floppy_NybblizeImage(const unsigned char *image, unsigned char *nybblized, unsigned char *skew)
|
||||
constexpr size_t floppy_trackGapSize = 64;
|
||||
constexpr size_t nybblizedSectorSize = 21 + 343 + 48;
|
||||
constexpr size_t nybblizedTrackSize = floppy_trackGapSize + 16 * nybblizedSectorSize;
|
||||
|
||||
void nybblizeSector(int trackIndex, int sectorIndex, const uint8_t *sectorBytes, uint8_t *sectorNybblized)
|
||||
{
|
||||
// Format of a sector is header (23) + nybbles (343) + footer (30) = 396
|
||||
// (short by 20 bytes of 416 [413 if 48 byte header is one time only])
|
||||
// hdr (21) + nybbles (343) + footer (48) = 412 bytes per sector
|
||||
// (not incl. 64 byte track marker)
|
||||
memset(sectorNybblized, 0xFF, nybblizedSectorSize); // Doesn't matter if 00s or FFs...
|
||||
|
||||
static unsigned char footer[48] = {
|
||||
0xDE, 0xAA, 0xEB, 0xFF, 0xEB, 0xFF, 0xFF, 0xFF,
|
||||
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
|
||||
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
|
||||
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
|
||||
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
|
||||
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
|
||||
uint8_t *p = sectorNybblized;
|
||||
|
||||
static unsigned char diskbyte[0x40] = {
|
||||
0x96, 0x97, 0x9A, 0x9B, 0x9D, 0x9E, 0x9F, 0xA6,
|
||||
0xA7, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB2, 0xB3,
|
||||
0xB4, 0xB5, 0xB6, 0xB7, 0xB9, 0xBA, 0xBB, 0xBC,
|
||||
0xBD, 0xBE, 0xBF, 0xCB, 0xCD, 0xCE, 0xCF, 0xD3,
|
||||
0xD6, 0xD7, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE,
|
||||
0xDF, 0xE5, 0xE6, 0xE7, 0xE9, 0xEA, 0xEB, 0xEC,
|
||||
0xED, 0xEE, 0xEF, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6,
|
||||
0xF7, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF };
|
||||
memcpy(p, floppy_sectorHeader, sizeof(floppy_sectorHeader)); // Set up the sectorIndex header
|
||||
|
||||
memset(nybblized, 0xFF, 232960); // Doesn't matter if 00s or FFs...
|
||||
p[5] = ((trackIndex >> 1) & 0x55) | 0xAA;
|
||||
p[6] = (trackIndex & 0x55) | 0xAA;
|
||||
p[7] = ((sectorIndex >> 1) & 0x55) | 0xAA;
|
||||
p[8] = (sectorIndex & 0x55) | 0xAA;
|
||||
p[9] = (((trackIndex ^ sectorIndex ^ 0xFE) >> 1) & 0x55) | 0xAA;
|
||||
p[10] = ((trackIndex ^ sectorIndex ^ 0xFE) & 0x55) | 0xAA;
|
||||
|
||||
unsigned char *p = nybblized;
|
||||
p += 21;
|
||||
|
||||
for(unsigned char trk=0; trk<35; trk++)
|
||||
{
|
||||
memset(p, 0xFF, 64); // Write gap 1, 64 bytes (self-sync)
|
||||
p += 64;
|
||||
// Convert the 256 8-bit bytes into 342 6-bit bytes.
|
||||
|
||||
for(unsigned char sector=0; sector<16; sector++)
|
||||
{
|
||||
memcpy(p, floppy_header, 21); // Set up the sector header
|
||||
for(int i=0; i<0x56; i++)
|
||||
{
|
||||
p[i] = ((sectorBytes[(i + 0xAC) & 0xFF] & 0x01) << 7)
|
||||
| ((sectorBytes[(i + 0xAC) & 0xFF] & 0x02) << 5)
|
||||
| ((sectorBytes[(i + 0x56) & 0xFF] & 0x01) << 5)
|
||||
| ((sectorBytes[(i + 0x56) & 0xFF] & 0x02) << 3)
|
||||
| ((sectorBytes[(i + 0x00) & 0xFF] & 0x01) << 3)
|
||||
| ((sectorBytes[(i + 0x00) & 0xFF] & 0x02) << 1);
|
||||
}
|
||||
|
||||
p[5] = ((trk >> 1) & 0x55) | 0xAA;
|
||||
p[6] = (trk & 0x55) | 0xAA;
|
||||
p[7] = ((sector >> 1) & 0x55) | 0xAA;
|
||||
p[8] = (sector & 0x55) | 0xAA;
|
||||
p[9] = (((trk ^ sector ^ 0xFE) >> 1) & 0x55) | 0xAA;
|
||||
p[10] = ((trk ^ sector ^ 0xFE) & 0x55) | 0xAA;
|
||||
p[0x54] &= 0x3F;
|
||||
p[0x55] &= 0x3F;
|
||||
memcpy(p + 0x56, sectorBytes, 256);
|
||||
|
||||
p += 21;
|
||||
const unsigned char * bytes = image;
|
||||
// XOR the data block with itself, offset by one byte,
|
||||
// creating a 343rd byte which is used as a cheksum.
|
||||
|
||||
bytes += (skew[sector] * 256) + (trk * 256 * 16);
|
||||
p[342] = 0x00;
|
||||
|
||||
// Convert the 256 8-bit bytes into 342 6-bit bytes.
|
||||
for(int i=342; i>0; i--)
|
||||
p[i] = p[i] ^ p[i - 1];
|
||||
|
||||
for(int i=0; i<0x56; i++)
|
||||
{
|
||||
p[i] = ((bytes[(i + 0xAC) & 0xFF] & 0x01) << 7)
|
||||
| ((bytes[(i + 0xAC) & 0xFF] & 0x02) << 5)
|
||||
| ((bytes[(i + 0x56) & 0xFF] & 0x01) << 5)
|
||||
| ((bytes[(i + 0x56) & 0xFF] & 0x02) << 3)
|
||||
| ((bytes[(i + 0x00) & 0xFF] & 0x01) << 3)
|
||||
| ((bytes[(i + 0x00) & 0xFF] & 0x02) << 1);
|
||||
}
|
||||
// Using a lookup table, convert the 6-bit bytes into disk bytes.
|
||||
|
||||
p[0x54] &= 0x3F;
|
||||
p[0x55] &= 0x3F;
|
||||
memcpy(p + 0x56, bytes, 256);
|
||||
for(int i=0; i<343; i++)
|
||||
p[i] = floppy_6BitsToBytes[p[i] >> 2];
|
||||
p += 343;
|
||||
|
||||
// XOR the data block with itself, offset by one byte,
|
||||
// creating a 343rd byte which is used as a cheksum.
|
||||
// Done with the nybblization, now for the epilogue...
|
||||
|
||||
p[342] = 0x00;
|
||||
memcpy(p, floppy_sectorFooter, sizeof(floppy_sectorFooter));
|
||||
// p += 48;
|
||||
}
|
||||
|
||||
for(int i=342; i>0; i--)
|
||||
p[i] = p[i] ^ p[i - 1];
|
||||
void floppy_NybblizeImage(const unsigned char *floppyByteImage, unsigned char *nybblizedImage, const unsigned char *skew)
|
||||
{
|
||||
// Format of a sector is header (23) + nybbles (343) + footer (30) = 396
|
||||
// (short by 20 bytes of 416 [413 if 48 byte header is one time only])
|
||||
// hdr (21) + nybbles (343) + footer (48) = 412 bytes per sector
|
||||
// (not incl. 64 byte track marker)
|
||||
|
||||
// Using a lookup table, convert the 6-bit bytes into disk bytes.
|
||||
for(unsigned char trackIndex = 0; trackIndex < 35; trackIndex++)
|
||||
{
|
||||
unsigned char *nybblizedTrack = nybblizedImage + trackIndex * nybblizedTrackSize;
|
||||
|
||||
for(int i=0; i<343; i++)
|
||||
p[i] = diskbyte[p[i] >> 2];
|
||||
p += 343;
|
||||
memset(nybblizedTrack, 0xFF, floppy_trackGapSize); // Write gap 1, 64 bytes (self-sync)
|
||||
|
||||
// Done with the nybblization, now for the epilogue...
|
||||
|
||||
memcpy(p, footer, 48);
|
||||
p += 48;
|
||||
}
|
||||
}
|
||||
for(unsigned char sectorIndex = 0; sectorIndex < 16; sectorIndex++)
|
||||
{
|
||||
const unsigned char * sectorBytes = floppyByteImage + (skew[sectorIndex] * 256) + (trackIndex * 256 * 16);
|
||||
nybblizeSector(trackIndex, sectorIndex, sectorBytes, nybblizedTrack + sectorIndex * nybblizedSectorSize);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// XXX readonly at this time
|
||||
|
|
@ -420,13 +426,13 @@ struct DISKIIboard : board_base
|
|||
throw "Couldn't read floppy";
|
||||
|
||||
floppy_present[number] = true;
|
||||
unsigned char *skew;
|
||||
const unsigned char *skew;
|
||||
if(strcmp(name + strlen(name) - 3, ".po") == 0) {
|
||||
printf("ProDOS floppy\n");
|
||||
skew = floppy_poSector;
|
||||
}
|
||||
else
|
||||
} else {
|
||||
skew = floppy_doSector;
|
||||
}
|
||||
floppy_NybblizeImage(floppy_image[number], floppy_nybblized[number], skew);
|
||||
}
|
||||
}
|
||||
|
|
@ -439,26 +445,26 @@ struct DISKIIboard : board_base
|
|||
{
|
||||
std::copy(diskII_rom, diskII_rom + 0x100, rom_C600.memory.begin());
|
||||
if(floppy0_name) {
|
||||
floppy_image[0] = new unsigned char[143360];
|
||||
floppy_image[0] = new (std::nothrow) unsigned char[143360];
|
||||
if(!floppy_image[0]) {
|
||||
throw "failed to allocate floppy_image[0]";
|
||||
}
|
||||
floppy_nybblized[0] = new unsigned char[232960];
|
||||
floppy_nybblized[0] = new (std::nothrow) unsigned char[232960];
|
||||
if(!floppy_nybblized[0]) {
|
||||
throw "failed to allocate floppy_nybblized[0]";
|
||||
}
|
||||
set_floppy(0, floppy0_name);
|
||||
set_floppy(0, floppy0_name);
|
||||
}
|
||||
if(floppy1_name) {
|
||||
floppy_image[1] = new unsigned char[143360];
|
||||
floppy_image[1] = new (std::nothrow) unsigned char[143360];
|
||||
if(!floppy_image[1]) {
|
||||
throw "failed to allocate floppy_image[1]";
|
||||
}
|
||||
floppy_nybblized[1] = new unsigned char[232960];
|
||||
floppy_nybblized[1] = new (std::nothrow) unsigned char[232960];
|
||||
if(!floppy_nybblized[1]) {
|
||||
throw "failed to allocate floppy_nybblized[1]";
|
||||
}
|
||||
set_floppy(1, floppy1_name);
|
||||
set_floppy(1, floppy1_name);
|
||||
}
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue