SBCF8 hello, world

f8hello.asm

;	SBCF8 hello, world
;	dasm f8blink.asm -f3 -of8blink.bin -Lf8blink.lst

UARTD	EQU	$FF00
UARTC	EQU	$FF01
	PROCESSOR F8
	ORG	$0000
	JMP	START
;
;	MESSAGE
MESG	DC	"hello, world"
	DC	$0D, $0A, 0
;
;	S1 -> 8251
PUTCH	XDC		;CHANGE MEMORY POINTER
PC1	DCI	UARTC	;8251 CONTROL REGISTER
	LM		;GET STATUS
	NI	$01	;CHECK TX ENABLE
	BZ	PC1	;IF NOT, REPEAT
	DCI	UARTD	;8251 DATA REGISTER
	LR	A,1	;SET CHARACTOR
	ST		;WRITE
	XDC		;CHANGE MEMORY POINTER
	POP		;RETURN
;
;	8251 -> S1
GETCH	XDC		;CHANGE MEMORY POINTER
GC1	DCI	UARTC	;8251 CONTROL REGISTER
	LM		;GET STATUS
	NI	$02	;CHECK RX DONE
	BZ	GC1	;IF NOT, REPEAT
	DCI	UARTD	;8251 DATA REGISTER
	LM		;GET CHARACTOR
	LR	1,A	;SET CHARACTOR
	XDC		;CHANGE MEMORY POINTER
	POP		;RETURN
;
;	PUT STRING
PUTS	LR	K,P	;SAVE RETURN ADDRESS
PS1	LM		;READ CHARACTOR
	CI	0	;CHECK END
	BZ	PS2	;IF END, BREAK
	LR	1,A	;SET CHARACTOR
	PI	PUTCH	;CALL PUTCH
	JMP	PS1	;REPEAT
PS2	PK		;RETURN BY K
;
;	SYSTEM INITIALIZE
START	INS	1	;8251 HARDWARE RESET
	NI	$7F
	OUTS	1
	OI	$80
	OUTS	1
	CLR		;ESCAPE
	DCI	UARTC
	ST
	DCI	UARTC
	ST
	DCI	UARTC
	ST
	LI	$40	;SOFTWARE RESET
	DCI	UARTC
	ST
	LI	$4E	;MODE
	DCI	UARTC
	ST
	LI	$37	;COMMAND
	DCI	UARTC
	ST
;
;	HELLO, WORLD
	DCI	MESG	;SET MESSAGE TOP ADDRESS
	PI	PUTS	;CALL PUTS
;
;	ECHOBACK
LOOP	PI	GETCH	;CALL GETCH
	PI	PUTCH	;CALL PUTCH
	JMP	LOOP	;REPEAT
;
	END