;
;	HELLO WORLD PROGRAM
;	VERSION 0
;
STATUS	EQU	1		;RDT STATUS PORT
DATA	EQU	2		;RDT DATA PORT
INMASK	EQU	0x80		;STATUS PORT BIT D0 = 7 WHEN KEYBOARD CHARACTER DATA AVAILABLE
OUTMASK	EQU	0x40		;STATUS PORT BIT D7 = 6 WHEN TERMINAL BUSY PROCESSING CHARACTER DATA
;
	ORG	0X0000		;PROGRAM START ADDRESS
;
	LXI	H, HW_MSG
;
AGAIN:	MOV	A,M		;CHARACTER->A
	ORA	A		;IF A=0 THEN JUMP DONE
	JZ	DONE
	MOV	C,A		;A->C
;
;	CHROUT - OUTPUT CHARACTER IN A TO RDT SCREEN
;
CHROUT:	IN 	STATUS		;STATUS BYTE -> A
	ANI	OUTMASK		;MASK TERMINAL BUSY BIT D7
	JNZ	CHROUT		;WAIT IF D7 = 1 - TERMINAL BUSY
	MOV	A,C		;C->A
	OUT	DATA		;SEND CHARACTER TO TEMINAL SCREEN
;
	INX	H		;HL+1->HL
	JMP	AGAIN		;GET NEXT CHARACTER
;
DONE:	HLT
;
;	PROGRAM END
;
;	DATA STORAGE
;
HW_MSG:	DB	25		;CLEAR SCREEN
	DM	'Hello World'
	DB	0
;