seg.binID &= (long) ~(0x70 << ((vbasLength - 1) * 7));

<< means shl

0x70 means $70

seg.binID:= seg.binID and LongInt($70 shl ((vbasLength - 1) * 7));

seg.binID:= seg.binID and LongInt(not ($70 shl ((vbasLength - 1) * 7)));