static void vc1541_sector_to_gcr(int track, int sector)
{
int i=0, j, offset, chksum=0;
if (vc1541->d64.data==NULL) return;
vc1541->head.data[i++]=0xff;
vc1541->head.data[i++]=0xff;
vc1541->head.data[i++]=0xff;
vc1541->head.data[i++]=0xff;
vc1541->head.data[i++]=0xff;
vc1541_sector_start();
vc1541_sector_data(8, &i);
chksum= sector^track
^vc1541->d64.data[D64_TRACK_ID1]^vc1541->d64.data[D64_TRACK_ID2];
vc1541_sector_data(chksum, &i);
vc1541_sector_data(sector, &i);
vc1541_sector_data(track, &i);
vc1541_sector_data(vc1541->d64.data[D64_TRACK_ID1], &i);
vc1541_sector_data(vc1541->d64.data[D64_TRACK_ID2], &i);
vc1541_sector_data(0xf, &i);
vc1541_sector_data(0xf, &i);
vc1541_sector_end(&i);
/* 5 - 10 gcr bytes cap */
gcr_double_2_gcr(0, 0, 0, 0, vc1541->head.data+i);i+=5;
gcr_double_2_gcr(0, 0, 0, 0, vc1541->head.data+i);i+=5;
vc1541->head.data[i++]=0xff;
vc1541->head.data[i++]=0xff;
vc1541->head.data[i++]=0xff;
vc1541->head.data[i++]=0xff;
vc1541->head.data[i++]=0xff;
vc1541_sector_data(0x7, &i);
chksum=0;
for (offset=d64_tracksector2offset(track,sector), j=0; j<256; j++) {
chksum^=vc1541->d64.data[offset];
vc1541_sector_data(vc1541->d64.data[offset++], &i);
}
vc1541_sector_data(chksum, &i);
vc1541_sector_data(0, &i); /* padding up */
vc1541_sector_data(0, &i);
vc1541_sector_end(&i);
gcr_double_2_gcr(0, 0, 0, 0, vc1541->head.data+i);i+=5;
gcr_double_2_gcr(0, 0, 0, 0, vc1541->head.data+i);i+=5;
}
int d64_getcrc(d64_image *image, int track, int sector)
{
int pos=d64_tracksector2offset(track, sector)>>8;
if (!image->crc) return 0;
return image->data[d64_tracksector2offset(image->tracks+1,0)+pos];
}