cbm stuff from greggs pull request

libsrc/cbm510/cpeekcolor.s

@@ -0,0 +1,24 @@
+;
+; 2016-02-28, Groepaz
+; 2017-06-19, Greg King
+;
+; unsigned char cpeekcolor (void);
+;
+
+        .export         _cpeekcolor
+
+        .import         CURS_X: zp, CRAM_PTR: zp
+
+        .include        "cbm510.inc"
+
+
+_cpeekcolor:
+        ldx     IndReg
+        lda     #$0F
+        sta     IndReg
+        ldy     CURS_X
+        lda     (CRAM_PTR),y    ; get color
+        stx     IndReg
+        and     #$0F
+        ldx     #>$0000
+        rts

libsrc/cbm510/doesclrscr.s

@@ -0,0 +1,16 @@
+;
+; 2016-06, Christian Groessler
+; 2017-07-05, Greg King
+;
+; unsigned char doesclrscrafterexit (void);
+;
+; Returns 0/1 if, after program termination, the screen isn't/is cleared.
+;
+
+        .import         return1
+
+; cc65's CBM510 programs switch to a display screen in the program RAM bank;
+; then, they switch back to the system bank when they exit.
+; The screen is cleared.
+
+        .export         _doesclrscrafterexit := return1