test_char_io_01.65s

; Basic test of char I/O emulation

	.ORG $0200
	
CHRGET	= $E000
PUTCH 	= $E000
TXTBUF	= $0400
CR 	= $0D
NL 	= $0A

START:	LDX #$00
PR1:	LDA PROMPT,X	;print prompt
	BEQ L0
	STA PUTCH
	INX
	BNE PR1
L0:	LDX #$00
GETTXT: LDA CHRGET	;get text from input
	BEQ GETTXT
	CMP #CR
	BEQ L1
	CMP #NL
	BEQ L1
	STA PUTCH	;echo char
	STA TXTBUF,X	;store char
	INX
	BNE GETTXT
L1:	LDA #NL		; add line break
	STA TXTBUF,X
	STA PUTCH
	INX
	LDA #CR
	STA TXTBUF,X
	STA PUTCH
	INX
	LDA #$00	; add null
	STA TXTBUF,X
	TAX
PRINT:	LDA TXTBUF,X	; print to output
	BEQ L2
	STA PUTCH
	INX
	BNE PRINT
L2:	BRK
	NOP
	JMP START
PROMPT:	.DB "Enter text:",0