From 679f5aa6756a5036e72259aa46fafbe2488610bc Mon Sep 17 00:00:00 2001
From: =?utf8?q?Stephan=20M=C3=BChlstrasser?= <stephan.muehlstrasser@web.de>
Date: Thu, 12 Feb 2015 20:54:47 +0100
Subject: [PATCH] Use constants for screen width and height.

---
 cfg/osic1p.cfg           | 2 +-
 libsrc/osic1p/_scrsize.s | 8 +++-----
 libsrc/osic1p/cputc.s    | 4 ++--
 libsrc/osic1p/crt0.s     | 7 -------
 libsrc/osic1p/extzp.inc  | 2 +-
 libsrc/osic1p/extzp.s    | 3 +--
 libsrc/osic1p/osic1p.inc | 2 ++
 7 files changed, 10 insertions(+), 18 deletions(-)

diff --git a/cfg/osic1p.cfg b/cfg/osic1p.cfg
index 59fdd34d8..4771639a6 100644
--- a/cfg/osic1p.cfg
+++ b/cfg/osic1p.cfg
@@ -7,7 +7,7 @@ SYMBOLS {
 }
 MEMORY {
     # for size of ZP see runtime/zeropage.s and c1p/extzp.s
-    ZP:       file = "", define = yes, start = $0002, size = $001A + $0006;
+    ZP:       file = "", define = yes, start = $0002, size = $001A + $0005;
     RAM:      file = %O, define = yes, start = %S, size = __HIMEM__ - __STACKSIZE__ - %S;
 }
 SEGMENTS {
diff --git a/libsrc/osic1p/_scrsize.s b/libsrc/osic1p/_scrsize.s
index 3b0d71c2f..337fe1ee7 100644
--- a/libsrc/osic1p/_scrsize.s
+++ b/libsrc/osic1p/_scrsize.s
@@ -10,12 +10,10 @@
         .export         screensize
 
         .include        "extzp.inc"
+        .include        "osic1p.inc"
 
 .proc   screensize
-
-        ldx     SCR_LINELEN
-        inx                     ; Variable is one less
-        ldy     #25
+        ldx     #(SCR_LINELEN + 1)
+        ldy     #(SCR_HEIGHT + 1)
         rts
-
 .endproc
diff --git a/libsrc/osic1p/cputc.s b/libsrc/osic1p/cputc.s
index 9cea78789..f6f285301 100644
--- a/libsrc/osic1p/cputc.s
+++ b/libsrc/osic1p/cputc.s
@@ -35,7 +35,7 @@ cputdirect:
 ; Advance cursor position
 
 advance:
-        cpy     SCR_LINELEN     ; xsize-1
+        cpy     #SCR_LINELEN    ; xsize-1
         bne     L3
         jsr     newline         ; new line
         ldy     #$FF            ; + cr
@@ -46,7 +46,7 @@ L3:     iny
 newline:
         inc     CURS_Y
         lda     CURS_Y
-        cmp     #24             ; screen height 25 lines hardcoded
+        cmp     #SCR_HEIGHT     ; screen height
         bne     plot
         lda     #0              ; wrap around to line 0
         sta     CURS_Y
diff --git a/libsrc/osic1p/crt0.s b/libsrc/osic1p/crt0.s
index 447b65c56..0db447bb0 100644
--- a/libsrc/osic1p/crt0.s
+++ b/libsrc/osic1p/crt0.s
@@ -28,13 +28,6 @@ _init:    ldx     #$FF                 ; Initialize stack pointer to $01FF
           txs
           cld                          ; Clear decimal mode
 
-; ---------------------------------------------------------------------------
-; Initialize screen width
-; TODO: Can initialization be done in a more idiomatic way?
-; TODO: Create function for changing screen width
-          lda     #$18
-          sta     SCR_LINELEN
-
 ; ---------------------------------------------------------------------------
 ; Set cc65 argument stack pointer
 
diff --git a/libsrc/osic1p/extzp.inc b/libsrc/osic1p/extzp.inc
index c5bb2b585..4aab34ff9 100644
--- a/libsrc/osic1p/extzp.inc
+++ b/libsrc/osic1p/extzp.inc
@@ -4,4 +4,4 @@
 
 ; ------------------------------------------------------------------------
 
-        .globalzp       CURS_X, CURS_Y, CURS_SAV, SCR_LINELEN, SCREEN_PTR
+        .globalzp       CURS_X, CURS_Y, CURS_SAV, SCREEN_PTR
diff --git a/libsrc/osic1p/extzp.s b/libsrc/osic1p/extzp.s
index dfa84a61c..95f9394dc 100644
--- a/libsrc/osic1p/extzp.s
+++ b/libsrc/osic1p/extzp.s
@@ -14,8 +14,7 @@
 CURS_X:         .byte   0
 CURS_Y:         .byte   0
 CURS_SAV:       .byte   0
-SCR_LINELEN:    .byte   24
 SCREEN_PTR:     .res    2
 
-; size 6
+; size 5
 ; Adjust size of this segment in osic1p.cfg if the size changes
diff --git a/libsrc/osic1p/osic1p.inc b/libsrc/osic1p/osic1p.inc
index e364277e0..58d63632f 100644
--- a/libsrc/osic1p/osic1p.inc
+++ b/libsrc/osic1p/osic1p.inc
@@ -5,3 +5,5 @@ RESET           := $FF00    ; Reset address, show boot prompt
 
 ; Other definitions
 VIDEORAMSIZE    = $0400     ; Size of C1P video RAM (1 kB)
+SCR_LINELEN     = $18       ; screen width - 1
+SCR_HEIGHT      = $18       ; screen height - 1
-- 
2.39.5