;	
;	Program to test string input
;	
;	Compile with:
;		cl65 -t none -o input_test.prg input_test.asm


;	I/O Page Addresses
CONS_IO		=$FF00

;	Variable Addresses
STR_BUF		=$0280			; 127 Bytes to 02FF (incl.)
STR_LEN		=$24			; Zero page index var


.FEATURE	STRING_ESCAPES

.WORD		$0200
.ORG		$0200

	start:	LDA #<s_prompt	; Put string pointer
			STA $F0			; for prompt text
			LDA #>s_prompt	; on the zero-page
			STA $F1			; and put the string
			JSR puts		; to the screen

	line:	LDX #$00		; Init str_buf index
	read:	LDA CONS_IO		; Read char
			BMI read		; Repeat until B7 is clear

			STA STR_BUF,X	; Store to input buffer

			CMP #$0A		; If input was newline
			BEQ output		; Jump to output

			CMP #$08		; If input was not backspace
			BNE echo		; skip backspace handling

			DEX				; Decrement text index (remove backspace)
			BMI line		; Buffer invali re-init line
			DEX				; Decrement text index (remove previous char)

	echo:	STA CONS_IO		; Echo input character
	
			INX				; Increment index
			BPL	read		; If index is under 128, continue
	
			DEX				; Decrement index to null-term pos
	output: LDA #$00		; Add null-terminator
			STA STR_BUF,X	; to end of input buffer

			LDA #$0A		; Print a newline
			STA CONS_IO

			LDA #<s_prefix	; Print output prefix
			STA $F0
			JSR puts

			LDA #<STR_BUF	; Print input string
			STA $F0
			JSR puts

			LDA #<s_suffix	; Print output suffix
			STA $F0
			JSR puts

	end:	JMP end			; Infinite loop to stall the CPU; Halt program

;	Put-String Subroutine (ZPP[$F0]) => ()
;	
	puts:	LDY #$00		; Init index
	@ch:	LDA ($F0),Y		; Get char from pointer at $00F0
			BEQ @end		; Skip to end if zero
			STA	CONS_IO		; Put char to screen
			INY				; Increment index
			JMP @ch			; Repeat until a zero is read
	@end:	RTS				; Return


s_prompt:	.ASCIIZ "Type something:\n> "
s_prefix:	.ASCIIZ "You said: '"
s_suffix:	.ASCIIZ "'\nCool!\n"