INT 21 - DOS 1+ - RANDOM BLOCK WRITE TO FCB FILE
AH = 28h
CX = number of records to write
DS:DX -> opened FCB (see AH=0Fh)
[DTA] = records to write
Return: AL = status
00h successful
01h disk full or file read-only
02h segment wrap in DTA
CX = number of records written
Notes:  write begins at current file position as specified in FCB; the file
position is updated after writing
if CX = 0000h on entry, no data is written; instead the file size is
adjusted to be the same as the file position specified by the random
record and record size fields of the FCB
if the data to be written is less than a disk sector, it is copied into
a DOS disk buffer, to be written out to disk at a later time
not supported by MS Windows 3.0 DOSX.EXE DOS extender
SeeAlso: AH=27h,AH=40h,AH=59h

See also: 2122

2128 - DOS 1+ - RANDOM BLOCK WRITE TO FCB FILE