From 3029d54edf8baabb2841f9a6f3d88bfc993ae3e8 Mon Sep 17 00:00:00 2001
From: mrb0nk500 <b0nk@b0nk.xyz>
Date: Thu, 19 Dec 2019 01:02:09 -0500
Subject: Added the B register, which is used for storing the remainder during
 a DIV instruction.

I also added the TAB, and TBA instructions, for
transfering between the Accumulator, and the
B register.
---
 test/input.s | 47 +++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 45 insertions(+), 2 deletions(-)

(limited to 'test')

diff --git a/test/input.s b/test/input.s
index a2725f6..95b4077 100644
--- a/test/input.s
+++ b/test/input.s
@@ -12,10 +12,15 @@ string2:
 	.byte "You typed, "
 end:
 	.byte $0
-x:
+scr_row:
 	.word $0
-tmp:
+scr_col:
 	.word $0
+a:
+	.word $0
+b:
+	.word $0
+
 ; Input buffer.
 .org $2000
 buffer:
@@ -93,6 +98,10 @@ esc:
 	cmp #$44	; Did the user press the left arrow?
 	beq left	; Yes, so move the cursor left.
 up:
+	lda scr_row
+	beq rset_a
+	dec scr_row
+	jsr update_pos
 	lda #$1B
 	sta $C001
 	lda #$5B
@@ -101,6 +110,8 @@ up:
 	sta $C001
 	jmp rset_a
 down:
+	inc scr_row
+	jsr update_pos
 	lda #$1B
 	sta $C001
 	lda #$5B
@@ -109,6 +120,11 @@ down:
 	sta $C001
 	jmp rset_a
 right:
+	lda scr_col
+	cmp #$50
+	beq rset_a
+	inc scr_col
+	jsr update_pos
 	lda #$1B
 	sta $C001
 	lda #$5B
@@ -117,6 +133,10 @@ right:
 	sta $C001
 	jmp rset_a
 left:
+	lda scr_col
+	beq rset_a
+	dec scr_col
+	jsr update_pos
 	lda #$1B
 	sta $C001
 	lda #$5B
@@ -125,8 +145,30 @@ left:
 	sta $C001
 	jmp rset_a
 
+update_pos:
+	lda #$1B
+	sta $C001
+	lda #$5B
+	sta $C001
+	lda scr_row
+	jsr uint_to_bcd
+	jmp spin
+
+uint_to_bcd:
+	div #$A
+	lsl #$4
+	sta a
+	tba
+	sta b
+	lda a
+	ora b
+	rts
+
 nl:
+	lda #$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.
 	ldy.w #$0	; Reset y, to print the result.
@@ -189,3 +231,4 @@ viewmem
 viewmem
 ;q
 done
+
-- 
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