Sector Map Disk of 2048 256-byte sectors (512KB) –sector map - vector of 2048 bits (64 longwords) »1 bit per sector »bit is 1 if sector is free, 0 if sector is used –find first free sector and claim it CLR.LD0Initial bit offset D0 = 0 LEAMAP,A0A0 points to sector bitmap MOVE.W#&63,D7Up to 64 fields to test L1BFFFO (A0){D0:32},D0If free sector found, Z=0 and D0 = offset from A0 DBNED7,L1Decr D7 until Z=0 or end BEQ FULLDisk full BFCLR(A0){D0:1}Claim sector, D0 = sector