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; -----------------------------------------------------------------------------
; iop definitions

; number of iops.
NIOPS		equ	4

; number of quadarts per iop
NQDS		equ	16

IOP1DPORT	equ	0CFH	; data port number of IOP1 (from the point of view of the host)
; (the data port number of IOP2 is 0BFH, of IOP3 is 0AFH, of IOP4 is 09FH.)

; INTVECRG byte (iop interrupt vector in the host system)
IOP1IVEC	equ	40H	; host interrupt vector from IOP1
; for IOP2 it is 42H, for IOP3 it is 44H, for IOP4 it is 46H

; number of iop channels.
; when the host commands the iop, it outputs a byte to the CMDREG.
; this byte has the iop channel number in the lower bits and the command number
; in the upper bits.
NCHANS		equ	32	; (must be a power of 2.  determines how many
				;  bits the iop channel number occupies in
				;  the lower bits of CMDREG.)
CHNMSK		equ	NCHANS - 1 ; channel number mask
CMDMSK		equ	not CHNMSK  ; command number mask
; iop port numbers (from the point of view of the iop)
CMDREG		equ	0	; input: command from host
STATREG		equ	0	; output: iop status to host
DATAREG		equ	1	; i/o: data to & from host
FLAGREG		equ	2	; input: status from host
CNTRLREG	equ	2	; output: control of interrupts, etc.
INTVECRG	equ	3	; output: interrupt vector for host's INTA

; STATREG flags or bits (output to host by iop)
SfCMDTBE	equ	1	; iop ready for a command from the host
SfDATRDA	equ	6	; iop has data available for the host
SfDATTBE	equ	7	; iop has read the data from the host

; STATREG messages using bits 2, 3, 4, and 5 (output to host by iop)
SmMAXMSG	equ	0fH<<2	; maximum numerical value of iop
				;		   message to host
SmERROR		equ	0fH<<2	; iop command error
SmWAIT		equ	0eH<<2	; wait until awaken by the iop
SmNODATA	equ	0dH<<2	; no data for host (EOF)
SmABORT		equ	SmNODATA; abort the host system call
SmLAST		equ	01H<<2	; last datum for host (delimiter)

; the iop indicates to the host the status of the previous command
; by outputting something to DATAREG (to explain to the host
; the reason for the error in the case of command error, or as a response
; to the command for some types of commands)
; and then outputting one of the following bytes to STATREG
;
;	^SfCMDTBE		iop ready for a new command from host
;	^SfCMDTBE | SmWAIT	iop cannot complete host's command now
;	^SfCMDTBE | SmERROR	iop command error

SGPHANGUP	equ	sigmax + 1	; modem has hung up, signal process
SGMAXIMUM	equ	SGPHANGUP	; IOP uses one signal more than Cromix
;		equ	sigmax + 2	; (spare)
SGWAKEUP	equ	sigmax + 3	; wake host up & then have host wake iop up
; value in c-register when .SETMODE is called for the device IOMEM
IOMD_RESET	equ	-99		; reset the IOP system
IOMD_POSITION	equ	0		; set memory location in the IOP
					;	   for reading & writing
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