home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
The C Users' Group Library 1994 August
/
wc-cdrom-cusersgrouplibrary-1994-08.iso
/
vol_200
/
223_02
/
freeio.mac
< prev
next >
Wrap
Text File
|
1989-02-23
|
896b
|
33 lines
;
; freeio(unit) by F.A.Scacchitti 9/12/84
;
; mark a buffer as free.
;
;
;
NBUFS EQU 8
FCBSIZE EQU 36 ;size, in bytes, of an FCB
BUFFER EQU 6 ;offset to disk sector buffer in I/O structure
FLAG EQU 33 ;file-type flag byte (in unused part of FCB)
FREEFLG EQU 128 ;This I/O structure is available for the taking
BUFSIZ EQU 1024 ;how long the sector buffer is
NULL EQU 0
;
EXTRN IOBUFS
;
;
FREEIO:: ;Mod 6 May 80 rj
POP B ;save rtn addr
POP H ;get buffer addr
PUSH H ;put the stack back together
PUSH B
LXI D,FLAG ;find flag byte
DAD D
MVI M,FREEFLG ;mark buffer as 'free'
LXI H,NULL ;return something
RET
END