;********************************************************
;*							*
;*	STORAGE ALLOCATION FOR 256 BYTE SCRATCH RAM	*
;*							*
;********************************************************
;
;
SIOVEC:	DEFW	RETI		;SIOB TX INTERRUPT
	DEFW	RETI		;SIOB EXTERNAL/STATUS INTERRUPT
	DEFW	SIOINT		;SIOB RX INTERRUPT
	DEFW	SIOERR		;SIOB SPECIAL RX CONDITION INTERRUPT
	DEFW	RETI		;SIOA TX INTERRUPT
	DEFW	RETI		;SIOA EXTERNAL/STATUS INTERRUPT
	DEFW	SIOINT		;SIOA RX INTERRUPT
	DEFW	SIOERR		;SIOA SPECIAL RX CONDITION INTERRUPT

CTCAV:	DEFW	KEYSRV		;CTCA0 INTERRUPT (KBD STROBE)
	DEFW	RETI
	DEFW	RETI
	DEFW	VSYNC		;CTCA3 INTERRUPT (CRT VERT SYNC)

CTCBV:	DEFW	RETI
	DEFW	RETI
	DEFW	MILLISEC	;CTCB2 INTERRUPT (MILLISECOND TIMER)
	DEFW	TIMER		;CTCB3 INTERRUPT (CLOCK TICK)

DMAVEC:	DEFW	RETI		;DMA READY INTERRUPT
	DEFW	RETI		;DMA MATCH INTERRUPT
	DEFW	RETI		;DMA END-OF-BLOCK INTERRUPT
	DEFW	RETI		;DMA MATCH/END INTERRUPT

	DEFW	0,0,0,0,0,0,0,0	;EXTRA INTERRUPT VECTORS
	DEFW	0,0,0,0,0,0,0,0
	DEFW	0,0,0,0,0,0,0,0
	DEFW	0,0,0,0,0,0,0,0
;
;
;	KEYBOARD DATA INPUT FIFO VARIABLES

FIFCNT:	DEFB	0		;FIFO DATA COUNTER
FIFIN:	DEFB	0		;FIFO INPUT POINTER
FIFOUT:	DEFB	0		;FIFO OUTPUT POINTER
FIFSIZ:	DEFB	32		;MAX FIFO SIZE PARAM
;
;
CONNUM:	DEFB	0		;CURRENT CONSOLE DEVICE# (0,1 OR 2)
SIOADR:	DEFB	0		;CONSOLE SIO CONTROL/DATA PORT NUMBER
	DEFB	0
;
;
CONFIG:	DEFB	00000001B	;STDBB AND D/S BITS FOR MONITOR
DSCOPY:	DEFB	DYSTAT+OFF	;CONTROL BYTE FOR D/S BANK SWITCH BIT
STDCPY:	DEFB	STDBB+OFF	;CONTROL BYTE FOR STD BANK SWITCH BIT
;
;
;	VECTORS FOR EXTRA FUNCTIONS IN KBD/SIO/TIMER INTERRUPTS
;	AND FOR EXTENDED MONITOR AND CRTOUT ROUTINES.
;
KBDVEC:	DEFW	STASH		;PARALLEL KEYBOARD
RDAVEC:	DEFW	STASH		;SIO RECEIVED DATA INTERRUPT
TIKVEC:	DEFW	CLOCK4		;ONE-SECOND INTERRUPT
MONVEC:	DEFW	EXT2		;EXTENDED MONITOR
CRTVEC:	DEFW	CRTOUT		;CRT OUTPUT DRIVER
;
;
;	CLOCK-TIMER INTERRUPT VARIABLES

TOD	EQU	$
SECS:	DEFB	0		;CLOCK SECONDS
MINS:	DEFB	0		;      MINUTES
HRS:	DEFB	0		;      HOURS
DAY:	DEFB	0		;CALENDAR DAY
MONTH:	DEFB	0		;	  MONTH
YEAR:	DEFB	0		;	  YEAR
;
TICKS:	DEFW	0		;CLOCK TICK INTERRUPT COUNTER
NTICKS:	DEFB	4		;NUMBER OF TICKS PER SECOND
TIKCNT:	DEFB	1		;PRESCALER FOR 1 SECOND TIMER
;
;
;	DISK I/O DRIVER VARIABLES

UNIT:	DEFB	255		;CURRENTLY SELECTED DISK#
TRACK:	DEFB	255		;TRACK POSITION OF SELECTED DRIVE
TRKTAB:	DEFB	255,255,255,255	;HEAD POSITIONS FOR 4 DRIVES
	DEFB	0,0,0,0		;DENSITY CONTROL BITS FOR 4 DRIVES
SPEED:	DEFB	6		;SEEK SPEED FOR 1771 COMMANDS
SETTLE:	DEFB	15		;HEAD SETTLING TIME
BLKSIZ:	DEFW	1024		;MAX DMA BLOCK SIZE FOR READ/WRITE
NSTOP:	DEFB	6*20		;NUMBER OF INDEX PULSES TILL DISK STOP
NREVS:	DEFB	3		;NUMBER OF INDEX PULSES BEFORE READY
DSKTYP:	DEFB	00000001B	;DISK TYPE / DENSITY INDICATOR
MAXRWT:	DEFB	5		;MAXIMUM RETRY NUMBER FOR DISK I/O

SECTOR:	DEFB	0		;SECTOR# FOR READ/WRITE SECTOR
CMDTYP:	DEFB	0		;COMMAND BYTE FOR READS/WRITES
RWTRY:	DEFB	0		;READ/WRITE RETRY COUNT
FNDTRY:	DEFB	0		;SEEK RETRY COUNT
ERRTYP:	DEFB	0		;ERROR STATUS FOR READ/WRITE ROUTINES
IOPTR:	DEFW	0		;DISK I/O BUFFER POINTER
SELCPY:	DEFB	0		;COPY OF DATA IN SELECT/MUX OUTPUTS
STPVEC:	DEFW	STEPX		;VECTOR FOR STEP FINITE STATE MACHINE
STPCMD:	DEFB	0		;... 179X STEP COMMAND BYTE
STPCNT:	DEFB	0		;... LOOP COUNT
STPDLY:	DEFB	0		;... DELAY COUNT
INUSE:	DEFB	0		;DISKS IN-USE FLAG FOR BACKGROUND
DSKCNT:	DEFB	0		;... DISK TURN-OFF COUNTER
RDYCNT:	DEFB	0		;... NOT-READY TIMER
OLDCTC:	DEFB	0		;... LAST CTCA1 COUNT
;
;
;
;	CRT OUTPUT DRIVER VARIABLES

RC	EQU	$		;ROW/COLUMN FOR CRT CURSOR LOCATION
ROW:	DEFB	0
COL:	DEFB	0
BLANK:	DEFB	' '		;CHARACTER USED FOR BLANK FILL
ATTRIB:	DEFB	00000011B	;CURRENT CHARACTER ATTRIBUTE BITS
GRMODE:	DEFB	00000000B	;MODE BITS FOR GRAPHICS MODE
ESCVEC:	DEFW	0		;POINTER FOR LEAD-IN SEQUENCE ROUTINES
ROWTMP:	DEFB	0
BELTIM:	DEFB	0		;BELL TURN-OFF DELAY IN 1/60 SECONDS
START:	DEFW	0		;CONTENTS OF 6845 START ADDRESS REG
NEWLIN:	DEFW	0		;RELATIVE ADDR OF NEW LINE AFTER SCROLL
MOVECS:	DEFB	0		;CURSOR-MOVE REQUEST FLAG
CURSOR:	DEFW	0		;OFFSET (0..2047) TO CURSOR LOCATION
OLDCSR:	DEFW	ATTMEM		;POINTER TO CURSOR IN ATTR MEMORY
CRTFLG:	DEFB	00000001B	;CRT PARAMETER BITS

AUTONL	EQU	0		;AUTO-NEWLINE
NOSCRL	EQU	1		;NO SCROLL
DSPTIM	EQU	2		;CLOCK TIME DISPLAY
;
;
;
;
;	FREE MEMORY LIST POINTER

FREPTR:	DEFW	TAIL
;
;