atari: split color.s into bordercolor.s and bgcolor.s

include/atari.h

@@ -491,5 +491,11 @@ extern void atrx15p2_tgi[];
 #define PxCTL_IRQ_STATUS         0x80
 
 
+/* The following #defines will cause the matching functions calls in conio.h
+** to be overlaid by macros with the same names, saving the function call
+** overhead.
+*/
+#define _textcolor(color)        1
+
 /* End of atari.h */
 #endif

libsrc/atari/bgcolor.s

@@ -1,15 +1,12 @@
 ;
-; Christian Groessler, 27-Dec-2002
+; Christian Groessler, 02-Apr-2019
 ;
 
-        .export         _textcolor, _bgcolor, _bordercolor
-        .import         return1
+        .export         _bgcolor
 
         .include        "atari.inc"
 
 
-_textcolor      =       return1
-
 _bgcolor:
         ldx     COLOR2  ; get old value
         sta     COLOR2  ; set new value
@@ -23,12 +20,3 @@ bright: lda     #0
         txa
         ldx     #0      ; fix X
         rts
-
-
-_bordercolor:
-        ldx     COLOR4  ; get old value
-        sta     COLOR4  ; set new value
-        txa
-        ldx     #0      ; fix X
-        rts
-

libsrc/atari/bordercolor.s

@@ -0,0 +1,15 @@
+;
+; Christian Groessler, 02-Apr-2019
+;
+
+        .export         _bordercolor
+
+        .include        "atari.inc"
+
+
+_bordercolor:
+        ldx     COLOR4  ; get old value
+        sta     COLOR4  ; set new value
+        txa
+        ldx     #0      ; fix X
+        rts