forums.nabu.ca

Code: Select all

BDOS		equ 05h		; standard cp/m entry
DCONIO		equ 06h		; direct console I/O
INPREQ		equ 0ffh	; console input request

		org 0100h

		ld de,msg			; print 'welcome' msg
		call pstr
loop:
		call getchar		; get a character
		or a			
		jr z,loop		; nothing, so loop
		
		call putchar		; print the character
		jr loop

getchar:	
		push	bc
		push	de
		ld	c,DCONIO	; direct console i/o
		ld	e,INPREQ	; input request
		call	BDOS		; any chr typed?
		pop	de		; if yes, (a)<--char
		pop	bc		; else    (a)<--00h (ignore chr)
		or	a				
		ret
;
putchar:					
		push	bc
		push	de
		push	af
		push	hl
		ld	c,DCONIO	; direct console i/o
		ld	e,a		; output char (a)
		call	BDOS
		pop	hl
		pop	af
		pop	de
		pop	bc
		ret

pstr:
		ld a,(de)		; get a character
		inc de			; bump pointer
		call putchar		; show character
		cp 0dh			; was it a cr?
		jr nz,pstr		; no, next character
		ret			; yes, returns

msg:		db	"Type something:",0ah, 0dh