;		BDOS symbols:

on		EQU	0ffffh
off		EQU	00000h

;	Special 8086 symbols:

b		equ	byte ptr 0
w		equ	word ptr 0

;	literal constants

enddir		EQU	0ffffh		;end of directory

;	file control block (fcb) constants

fcblen		EQU	32		;fcb length
empty		EQU	0e5h		;empty directory entry
lstrec		EQU	127		;last record# in extent
recsiz		EQU	128		;record size
dirrec		EQU	recsiz/fcblen	;directory elts / record
dskshf		EQU	2		;log2(dirrec)
dskmsk		EQU	dirrec-1
fcbshf		EQU	5		;log2(fcblen)
maxext		EQU	31		;largest extent number
maxmod		EQU	63		;largest module number
fwfmsk		EQU	80h		;file write flag is high
					;order modnum
namlen		EQU	15		;name length
;lstfcb 	EQU	fcblen-1

drv		EQU	0		;drive field
f1		EQU	1		;file name byte 1 to 8
;f2		EQU	2
;f3		EQU	3
;f4		EQU	4
f5		EQU	5
;f6		EQU	6
f7		EQU	7
f8		EQU	8

;	reserved file indicators

rofile		EQU	9		;t1' -> read/only file
sysfil		EQU	10		;t2' -> system file
ARCHIV		EQU	11		;t3' -> FILE HAS BEEN ARCHIVED
extnum		EQU	12		;extent number field
chksum		EQU	13		;unfilled bytes field
modnum		EQU	14		;data module number
reccnt		EQU	15		;record count field
dskmap		EQU	16		;disk map field
nxtrec		EQU	fcblen
ranrec		EQU	nxtrec+1	;random record field (3 bytes)