I observed long time ago that floppy images created by Steem disk manager
missing correct second FAT init. It is likely harmless bug, as TOS is tolerant
on. Still, I like to see it done properly, especially as those images may be
used with DOS, Windows, which are not so tolerant.
The fixing, in diskman.cpp :
bool TDiskManager::CreateDiskImage(char *STName,int Sectors,int
SecsPerTrack,int Sides)
{
FILE *f=fopen(STName,"wb");
if (f){
char zeros[512];
ZeroMemory(zeros,sizeof(zeros));
for (int n=0;n<Sectors;n++) fwrite(zeros,1,512,f);
//LITTLE-ENDIAN ONLY
******************************************************
int buf;
fseek(f,0,SEEK_SET);
fputc(0xeb,f);fputc(0x30,f);
fseek(f,8,SEEK_SET); // Skip loader
fputc(BYTE(rand()),f);fputc(BYTE(rand()),f);fputc(BYTE(rand()),f); //Serial number
buf=512; fwrite(&buf,2,1,f); //Bytes Per Sector
buf=2; fwrite(&buf,1,1,f); //Sectors Per Cluster
buf=1; fwrite(&buf,2,1,f); //RES
buf=2; fwrite(&buf,1,1,f); //FATs
buf=112; fwrite(&buf,2,1,f); //Dir Entries
buf=Sectors; fwrite(&buf,2,1,f);
buf=249; fwrite(&buf,1,1,f); //Unused - MSDOS signo in fact
// 3 sectors per FAT is enough up to 1MB disk capacity
// 5 sectors per FAT up to 1700 KB - so HD, 20 sectors per track too
if (Sectors<2000) buf=3;
else buf=5;
fwrite(&buf,2,1,f); //Sectors Per FAT
buf=SecsPerTrack; fwrite(&buf,2,1,f);
buf=Sides; fwrite(&buf,2,1,f);
buf=0; fwrite(&buf,2,1,f); //Hidden Sectors
fseek(f,510,SEEK_SET);
fputc(0x97,f);fputc(0xc7,f); // dummy ?
fputc(0xf0,f);fputc(0xff,f);fputc(0xff,f); // First FAT begin
// Second FAT too ! :
if (Sectors<2000) fseek(f,2048,SEEK_SET);
else fseek(f,3072,SEEK_SET);
fputc(0xf0,f);fputc(0xff,f);fputc(0xff,f); // Second FAT begin
fclose(f);
DeleteFile(Str(STName)+".steembpb");
return true;
}
return 0;
}
Original issue reported on code.google.com by pet...@8bitchip.info on 21 Dec 2011 at 9:48
Original issue reported on code.google.com by
pet...@8bitchip.infoon 21 Dec 2011 at 9:48Attachments: