;
; STATUS BYTES
;
BASE	EQU		70H
ERROR	EQU		BASE
DSKRDY	EQU		BASE+1
BLKTAG	EQU		BASE+2
;
; INTERFACE COMMANDS
;
IOPBL	EQU		BASE+1
IOPBH	EQU		BASE+2
DSKRST	EQU		BASE+7
;
; IOPB
;
IOPB:	
DSKCMD:		DB	0		; DSK NO. BITS 7,6; INT CNTL BITS 5,4; LENGTH BIT 3
						; DISK CMD BITS 2,1,0 
SECTORS:	DB	1		; HOW MANY SECTORS TO TRANSFER
TRACK:		DB	0		; WHAT TRACK
SECTOR:		DB	1		; WHAT SECTOR
BUFFER:		DW	4000H	; WHERE IS BUFFER
SECLENG:	DB	128		; LENGTH OF A SECTOR
DMARK:		DB	O		; DATA MARK 7,6; RETRY 5,4; IBM 3, BUFF STRT 2,1,0
BTR:		DB	0		; BLK TAG RESULT 7; BLK TAG 5,4,3,2,1,0
DSIDE:		DB	0		; DSIDE 5; DD/SD 1; CMD CHAIN 0
NEXTIOPB:	DW	IOPB+13		; NEXT IOPB IN CHAIN
 
MARK	EQU		IOPB+