New _randomize() function, do some cleanup on apple2.inc

git-svn-id: svn://svn.cc65.org/cc65/trunk@1496 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/apple2/Makefile

@@ -25,6 +25,7 @@ S_OBJS=	_scrsize.o	\
 	ctype.o		\
 	cvline.o	\
 	kbhit.o		\
+        randomize.o     \
 	read.o		\
 	revers.o	\
 	where.o		\

libsrc/apple2/apple2.inc

@@ -1,22 +1,7 @@
-; Break vector
-BRKVec  = $03F0
 
-; Goto Dos
+;-----------------------------------------------------------------------------
-RESTOR	=	$03D0
+; Zero page stuff
 
-; Soft switches
-;
-; write to USEROM to enable apple rom C000-CFFF
-USEROM	=	$C007
-; 80 column card switches
-C80ON	=	$C00C
-C80OFF	=	$C00D
-RD80COL	=	$C01F
-PG2OFF	=	$C054
-PG2ON	=	$C055
-RDPAGE2	=	$C01C
-
-; Text routines
 MIN_X	=	$20
 MAX_X	=	$21
 MIN_Y	=	$22
@@ -25,10 +10,31 @@ CH	=	$24
 CV	=	$25
 BASL	=	$28
 TEXTTYP	=	$32
+RNDL    =       $4E             ; Random value, low byte
+RNDH    =       $4F             ; Random value, high byte
 MEMSIZE	=	$73		; Highest free RAM location
-HOME	=	$FC58
+
-VTABZ	=	$FC24
+;-----------------------------------------------------------------------------
-COUT    = 	$FDED
+; Vectors
+
+BRKVec  =       $03F0           ; Break vector
+RESTOR	=	$03D0           ; Goto Dos
+
+;-----------------------------------------------------------------------------
+; Hardware
+
+; Soft switches
+;
+; Write to USEROM to enable apple rom C000-CFFF
+USEROM	=       $C007
+
+; 80 column card switches
+C80ON	=	$C00C
+C80OFF	=	$C00D
+RD80COL	=	$C01F
+PG2OFF	=	$C054
+PG2ON	=	$C055
+RDPAGE2	=	$C01C
 
 ; Keyboard entries
 RDKEY	=	$FD0C
@@ -39,8 +45,16 @@ KEY_STROBE       = $C000
 OPEN_APPLE =    $C061
 CLOSED_APPLE =  $C062
 
+;-----------------------------------------------------------------------------
+; ROM routines
+
+; Text output and helpers
+HOME	=	$FC58
+VTABZ	=	$FC24
+COUT    = 	$FDED
+
 ; Graphics entry points, by cbmnut (applenut??) cbmnut@hushmail.com
-WHITE   = $01     ;white for $1c, I think...
+WHITE   = $01           ; White for $1c, I think...
 
 COLOR   = $1C           ; Current plot color
 

libsrc/apple2/randomize.s

@@ -0,0 +1,17 @@
+;
+; Ullrich von Bassewitz, 07.11.2002
+;
+; void _randomize (void);
+; /* Initialize the random number generator */
+;
+
+    	.export	       	__randomize
+	.import		_srand
+
+        .include        "apple2.inc"
+
+__randomize:
+        ldx     RNDH            ; Use random value supplied by ROM
+        lda     RNDL
+        jmp     _srand          ; Initialize generator
+