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Magnum One
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Magnum One (Mid-American Digital) (Disc Manufacturing).iso
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d12
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jazlib.arc
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JZGETCLS.C
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1988-12-18
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982b
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34 lines
/*
┌────────────────────────────────────────────────────────────────────────────┐
│jzgetcls.c │
│Return a cluster given a two byte cluster word from a lookup │
│into the file allocation table. │
│ │
│See jzgetfat.dmo for examples │
│ │
│ (C) JazSoft Software by Jack A. Zucker (301) 794-5950 │
└────────────────────────────────────────────────────────────────────────────┘
*/
jzgetcls(ffat , fcluster , fbigfat)
char *ffat;
int fcluster;
int fbigfat; /* true on 20mg or > disks */
{
int wcluster,woddeven;
if (fbigfat) {
memcpy(&wcluster , ffat + (fcluster << 1),2); /* get cluster */
return(wcluster);
}
woddeven = 3 * fcluster;
memcpy(&wcluster , ffat + (woddeven >> 1),2); /* get cluster */
if (woddeven & 1)
return(wcluster >> 4); /* get rid of low nibble */
else
return(wcluster & 0xFFF); /* get rid of high nibble */
}