.TITLE	LOADER	load intel-hex data
	.IDENT	/01.03/
	.LIST	ME
	.ENABL	REG
;
; LOADER loads intel-hex data from the console device
; Register usage:	R5: byte count
;			R4: address
;			R3: record type
;			R2: data byte
;			R1: checksum
;			R0: temporary storage
;
; 30-SEP-2004	H. Rosenfeld
;

	TKS=177560
	TKB=177562
	TPS=177564
	TPB=177566
	PRCHAR=76

START:	RESET
	MOV	PC,R0
	CMP	-(R0),-(R0)
	MOV	R0,SP
1$:	MOV	#15,R0
	JSR	PC,PUTC
	MOV	#12,R0
	JSR	PC,PUTC
	MOV	#PRCHAR,R0
	JSR	PC,PUTC		; cr, lf, prompt
	JSR	PC,GETC
	JSR	PC,PUTC
	CMP	#':,R0
	BNE	ERROR
	CLR	R1
	JSR	PC,GETH
	MOV	R0,R5
	ASH	#4,R5
	JSR	PC,GETH
	ADD	R0,R5
	ADD	R5,R1
	JSR	PC,GETH
	MOV	R0,R4
	ASH	#4,R4
	JSR	PC,GETH
	ADD	R0,R4
	ADD	R4,R1
	SWAB	R4
	JSR	PC,GETH
	MOV	R0,R3
	ASH	#4,R3
	JSR	PC,GETH
	ADD	R0,R3
	ADD	R3,R1
	ADD	R3,R4
	JSR	PC,GETH
	MOV	R0,R3
	ASH	#4,R3
	JSR	PC,GETH
	ADD	R0,R3
	ADD	R3,R1
	TST	R3
	BEQ	2$
	DEC	R3
	BNE	ERROR
	INC	R3
	BR	3$
2$:	JSR	PC,GETH
	MOV	R0,R2
	ASH	#4,R2
	JSR	PC,GETH
	ADD	R0,R2
	ADD	R2,R1
	MOVB	R2,(R4)+
	SOB	R5,2$
3$:	JSR	PC,GETH
	MOV	R0,R2
	ASH	#4,R2
	JSR	PC,GETH
	ADD	R0,R2
	ADD	R2,R1
	TSTB	R1
	BNE	ERROR
	JSR	PC,GETC
	TST	R3
	BEQ	1$
	HALT
ERROR:	MOV	#7,R0
	JSR	PC,PUTC
	JSR	PC,PUTC
	JSR	PC,PUTC
	HALT

PUTC:	TSTB	@#TPS		; console printer ready?
	BPL	PUTC		; nay.
	MOVB	R0,@#TPB	; write character
	RTS	PC

GETC:	TSTB	@#TKS		; character in buffer?
	BPL	GETC		; nay.
	MOVB	@#TKB,R0	; read character
	RTS	PC

GETH:	JSR	PC,GETC
	JSR	PC,PUTC
	SUB	#'A,R0
	BPL	1$
	ADD	#7,R0
1$:	ADD	#12,R0
	RTS	PC

	.END	START