From ab2ca897ce3d0b4084fccebe400566a080d6e32c Mon Sep 17 00:00:00 2001
From: Arne Schmitz <arne.schmitz@gmx.net>
Date: Sun, 16 Mar 2025 17:04:25 +0100
Subject: [PATCH] pure asm implementation of bsplot

---
 include/conio.c | 108 +++++++++++++++++++++++++++++++-----------------
 1 file changed, 71 insertions(+), 37 deletions(-)

diff --git a/include/conio.c b/include/conio.c
index 4a6014d..790be25 100644
--- a/include/conio.c
+++ b/include/conio.c
@@ -134,8 +134,77 @@ __asm bsinit
 #elif defined(__CBMPET__)
 #define bsout	0xffd2
 #define bsin	0xffe4
-__asm bsplot{
-    /* no equivalent on PET */
+/* This is inspired by the cc65 source code from pet/cputc.s */    
+#define CURS_X $c6
+#define CURS_Y $d8
+#define SCREEN_PTR $c4
+#define SCR_LINELEN $d5
+__asm bsplot
+{
+	sty CURS_X
+	stx CURS_Y
+plot:	ldy CURS_Y
+	lda ScrLo,y
+	sta SCREEN_PTR
+	lda ScrHi,y
+	ldy SCR_LINELEN
+	cpy #40+1
+	bcc col80
+	asl SCREEN_PTR              /* 80 column mode */
+	rol
+col80:	ora #$80                    /* Screen at $8000 */
+	sta SCREEN_PTR+1
+	rts
+ScrLo:	byt 0x00
+	byt 0x28
+	byt 0x50
+	byt 0x78
+	byt 0xA0
+	byt 0xC8
+	byt 0xF0
+	byt 0x18
+	byt 0x40
+	byt 0x68
+	byt 0x90
+	byt 0xB8
+	byt 0xE0
+	byt 0x08
+	byt 0x30
+	byt 0x58
+	byt 0x80
+	byt 0xA8
+	byt 0xD0
+	byt 0xF8
+	byt 0x20
+	byt 0x48
+	byt 0x70
+	byt 0x98
+	byt 0xC0
+ScrHi:	byt 0x00
+	byt 0x00
+	byt 0x00
+	byt 0x00
+	byt 0x00
+	byt 0x00
+	byt 0x00
+	byt 0x01
+	byt 0x01
+	byt 0x01
+	byt 0x01
+	byt 0x01
+	byt 0x01
+	byt 0x02
+	byt 0x02
+	byt 0x02
+	byt 0x02
+	byt 0x02
+	byt 0x02
+	byt 0x02
+	byt 0x03
+	byt 0x03
+	byt 0x03
+	byt 0x03
+	byt 0x03
 }
 __asm bsinit
 {
@@ -352,40 +421,6 @@ void textcursor(bool show)
 
 void gotoxy(char cx, char cy)
 {
-#ifdef __CBMPET__
-    /* This is inspired by the cc65 source code from pet/cputc.s */    
-#define CURS_X $c6
-#define CURS_Y $d8
-#define SCREEN_PTR $c4
-#define SCR_LINELEN $d5
-
-    static const char ScrLo[] = { 0x00, 0x28, 0x50, 0x78, 0xA0, 0xC8, 0xF0, 0x18,
-                                  0x40, 0x68, 0x90, 0xB8, 0xE0, 0x08, 0x30, 0x58,
-                                  0x80, 0xA8, 0xD0, 0xF8, 0x20, 0x48, 0x70, 0x98,
-                                  0xC0 };
-
-    static const char ScrHi[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
-                                  0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x02, 0x02,
-                                  0x02, 0x02, 0x02, 0x02, 0x03, 0x03, 0x03, 0x03,
-                                  0x03 };
-    __asm {
-            lda     cx
-            sta     CURS_X
-            lda     cy
-            sta     CURS_Y
-            ldy     CURS_Y
-            lda     ScrLo,y
-            sta     SCREEN_PTR
-            lda     ScrHi,y
-            ldy     SCR_LINELEN
-            cpy     #40+1
-            bcc     col80
-            asl     SCREEN_PTR                     /* 80 column mode */
-            rol
-    col80:  ora     #$80                    /* Screen at $8000 */
-            sta     SCREEN_PTR+1
-    }
-#else
 	__asm
 	{
 		ldx	cy
@@ -393,7 +428,6 @@ void gotoxy(char cx, char cy)
 		clc
 		jsr bsplot
 	}
-#endif
 }
 
 void textcolor(char c)