INT 21 - DOS 1+ - SET RANDOM RECORD NUMBER FOR FCB
AH = 24h
DS:DX -> opened FCB (see AH=0Fh)
Notes:  computes the random record number corresponding to the current record
number and record size, then stores the result in the FCB
normally used when switching from sequential to random access
not supported by MS Windows 3.0 DOSX.EXE DOS extender
SeeAlso: AH=27h,AH=42h

See also: 2121

2124 - DOS 1+ - SET RANDOM RECORD NUMBER FOR FCB