Fixed some bugs in both the assembly language

monitor, and the cursor movement routines for SuBAsm.

1 files changed, 162 insertions, 68 deletions

diff --git a/test/input.s b/test/input.s
index 95b4077..169372f 100644
--- a/test/input.s
+++ b/test/input.s
@@ -6,23 +6,27 @@
 
 ; Initalize some variables.
 .org $1000
-string:
-	.byte "Please, type something.\n"
-string2:
-	.byte "You typed, "
-end:
-	.byte $0
 scr_row:
-	.word $0
+	.byte $0
 scr_col:
-	.word $0
+	.byte $0
 a:
 	.word $0
 b:
 	.word $0
+c:
+	.word $0
+d:
+	.word $0
+string:
+	.byte "Please, type something.\n"
+string2:
+	.byte "You typed, "
+end:
+	.byte $0
 
 ; Input buffer.
-.org $2000
+.org $0000
 buffer:
 
 ; Main program
@@ -42,7 +46,7 @@ clr_buf:
 
 start:
 	ldx.w #$0	; Reset x.
-	ldy #$0		; Reset y.
+	ldy.w #$0	; Reset y.
 	jmp print
 
 rset_a:
@@ -66,6 +70,14 @@ print:
 	beq rset_a	; Did we find a null terminator?
 	sta $C001	; Print character.
 	inx		; Increment offset.
+	cmp #$A
+	beq inc_row
+	inc scr_col
+	jmp print
+inc_row:
+	inc scr_row
+	lda #$0
+	sta scr_col
 	jmp print	; Keep printing more characters.
 
 getchar:
@@ -79,98 +91,157 @@ getchar:
 	cmp #$7F
 	beq bs		; Did the user type a backspace?
 echo:
+	sta a
+	ldx scr_col
+	cpx #$79
+	bne echo_print
+linewrap:
+	inc scr_row
+	ldx #$0
+	stx scr_col
+	jsr update_pos
+echo_print:
+	lda a
 	sta $C001	; Echo typed character.
+	inc scr_col	; Increment the cursor's x coordinate.
 	sta buffer, y	; Store typed character into the input buffer.
-	iny		; Increment buffer offset.
-	jmp rset_a	; We are not, so add the backspace to the buffer.
+	iny		; Increment the buffer offset.
+	jmp rset_a	; Start getting user input.
 
 esc:
 	lda $C000	; Skip the '['.
 	lda $C000	; Get the next character.
-	beq read	; We have an error, so discard it, and read the next character.
+	beq read	; We have an error, so discard it, and go back to getting user input.
 	lda $C002	; Get the escape code.
-	cmp #$41	; Did the user press the up arrow?
+	sta c		; Store the escape code, until we need it.
+	jsr isup	; Check if the user pressed up.
+	lda d
+	cmp #$0
+	bne esc_end
+	jsr isdown	; Check if the user pressed down.
+	lda d
+	cmp #$0
+	bne esc_end
+	lda #$0
+	jsr isleft	; Check if the user pressed left.
+	lda d
+	cmp #$0
+	bne esc_end
+	jsr isright	; Check if the user pressed right.
+esc_end:
+	lda #$0
+	sta d
+	jmp rset_a	; Go back to getting user input.
+
+isup:
+	lda scr_row	; Is the cursor at the top of the screen?
+	beq isup_done	; Yes, so return.
+	lda c		; No, so load the escape code back into the accumulator.
+	cmp #$41	; Did the user press the up arrow key?
 	beq up		; Yes, so move the cursor up.
-	cmp #$42	; Did the user press the down arrow?
+isup_done:
+	rts		; End of isup.
+
+isdown:
+	lda scr_row	; Start checking the y coordinate of the cursor.
+	cmp #$17	; Is the cursor at the bottom of the screen?
+	beq isdown_done	; Yes, so return.
+	lda c		; No, so load the escape code back into the accumulator.
+	cmp #$42	; Did the user press the down arrow key?
 	beq down	; Yes, so move the cursor down.
-	cmp #$43	; Did the user press the right arrow?
+isdown_done:
+	rts		; End of isdown.
+
+isright:
+	lda scr_col	; Start checking the x coordinate of the cursor.
+	cmp #$4F	; Is the cursor at the far right of the screen?
+	beq isright_end	; Yes, so return.
+	lda c		; No, so load the escape code back into the accumulator.
+	cmp #$43	; Did the user press the right arrow key?
 	beq right	; Yes, so move the cursor right.
-	cmp #$44	; Did the user press the left arrow?
+isright_end:
+	rts		; End of isright.
+
+isleft:
+	lda scr_col	; Is the cursor at the far left of the screen?
+	beq isleft_done	; Yes, so return.
+	lda c		; No, so load the escape code back into the accumulator.
+	cmp #$44	; Did the user press the left arrow key?
 	beq left	; Yes, so move the cursor left.
+isleft_done:
+	rts		; End of isleft.
+
 up:
-	lda scr_row
-	beq rset_a
 	dec scr_row
 	jsr update_pos
-	lda #$1B
-	sta $C001
-	lda #$5B
-	sta $C001
-	lda #$41
-	sta $C001
-	jmp rset_a
+	lda #$1
+	sta d
+	jmp isup_done
 down:
 	inc scr_row
 	jsr update_pos
-	lda #$1B
-	sta $C001
-	lda #$5B
-	sta $C001
-	lda #$42
-	sta $C001
-	jmp rset_a
+	lda #$1
+	sta d
+	jmp isdown_done
 right:
-	lda scr_col
-	cmp #$50
-	beq rset_a
 	inc scr_col
 	jsr update_pos
-	lda #$1B
-	sta $C001
-	lda #$5B
-	sta $C001
-	lda #$43
-	sta $C001
-	jmp rset_a
+	jmp isright_end
 left:
-	lda scr_col
-	beq rset_a
 	dec scr_col
 	jsr update_pos
-	lda #$1B
-	sta $C001
-	lda #$5B
-	sta $C001
-	lda #$44
-	sta $C001
-	jmp rset_a
+	lda #$1
+	sta d
+	jmp isleft_done
 
 update_pos:
-	lda #$1B
-	sta $C001
-	lda #$5B
-	sta $C001
-	lda scr_row
-	jsr uint_to_bcd
-	jmp spin
+	lda #$1B	; Print an escape character
+	sta $C001	; to the screen.
+	lda #$5B	; Print '['
+	sta $C001	; to the screen, and start the escape sequence.
+	jsr getrow	; Start printing the row number to the screen.
+	jsr getcol	; Start printing the column number to the screen.
+	lda #$48	; Print 'H'
+	sta $C001	; to the screen.
+	rts		; End of update_pos.
+getrow:
+	lda scr_row	; Get the cursor's y coordinate.
+	div #$A		; Divide A by 10.
+	adc #$30	; Convert it to ascii, and
+	sta $C001	; print to the screen.
+	tba		; Get the remainder.
+	adc #$30	; Convert it to ascii, and
+	sta $C001	; print to the screen.
+	rts		; End of getrow.
+getcol:
+	lda #$3B	; Print ';'
+	sta $C001	; to the screen.
+	lda scr_col	; Get the cursor's x coordinate.
+	div #$A		; Divide A by 10.
+	adc #$30	; Convert it to ascii, and
+	sta $C001	; print to the screen.
+	tba		; Get the remainder.
+	adc #$30	; Convert it to ascii, and
+	sta $C001	; print to the screen.
+	rts		; End of getrow.
 
 uint_to_bcd:
-	div #$A
-	lsl #$4
-	sta a
-	tba
-	sta b
-	lda a
-	ora b
-	rts
+	div #$A		; Divide A by 10.
+	lsl #$4		; Shift the result left by 4 bits.
+	sta a		; Store the result for later.
+	tba		; Get the remainder.
+	sta b		; Store the remainder for later.
+	lda a		; Get the result.
+	ora b		; Or the result, with the remainder.
+	rts		; We've converted the value to BCD, so return.
 
 nl:
 	lda #$A
 	sta $C001
 	inc scr_row
-	jsr update_pos
 	lda #$0		; Replace newline with a null terminator.
 	sta buffer, y	; Store said terminator into the input buffer.
+	sta scr_col
 	ldy.w #$0	; Reset y, to print the result.
 	jmp result
 
@@ -179,6 +250,7 @@ back:
 	lda #$0		; Put a null terminator, in place of the backspace.
 	sta buffer, y	; Place it into the input buffer.
 	dey		; Decrement buffer offset.
+	dec scr_col
 	jmp read	; Get next character.
 
 bs:
@@ -187,9 +259,19 @@ bs:
 	jmp back	; We are not, so add the backspace to the buffer.
 
 result:
+	ldx scr_col
+	cpx #$79
+	bne result_print
+linewrap:
+	inc scr_row
+	ldx #$0
+	stx scr_col
+	jsr update_pos
+result_print:
 	lda string2, y
 	beq rset_y	; Reset y, if we hit the null terminator.
 	sta $C001	; Print 'You have typed, '
+	inc scr_col	; Increment the cursor's x coordinate.
 	iny		; Increment offset.
 	jmp result	; Keep printing.
 
@@ -199,9 +281,19 @@ rset_y:
 	jmp print_buf	; Print the input buffer.
 
 print_buf:
+	ldx scr_col
+	cpx #$79
+	bne buf_print
+linewrap:
+	inc scr_row
+	ldx #$0
+	stx scr_col
+	jsr update_pos
+buf_print:
 	lda buffer, y	; Get a character from the input buffer.
 	beq spin	; Are we done with printing the buffer?
 	sta $C001	; Print said character.
+	inc scr_col	; Increment the cursor's x coordinate.
 	iny
 	jmp print_buf	; Keep printing the buffer.
 
@@ -229,6 +321,8 @@ spin:
 viewmem
 .org $8100
 viewmem
+.org $8200
+viewmem
 ;q
 done