Updated the cx16 library to the Commander X16's ROM prerelease 37.

libsrc/cx16/cpeekcolor.s

@@ -1,5 +1,5 @@
 ;
-; 2019-09-25, Greg King
+; 2020-04-30, Greg King
 ;
 ; unsigned char cpeekcolor (void);
 ; /* Return the colors from the current cursor position. */
@@ -12,8 +12,15 @@
 
 _cpeekcolor:
         php
+        lda     CURS_FLAG       ; is the cursor currently off?
+        bne     @L1
         sei                     ; don't let cursor blinking interfere
-        stz     VERA::CTRL      ; use port 0
+        ldx     CURS_STATE      ; is cursor currently displayed?
+        beq     @L1             ; jump if not
+        lda     CURS_COLOR      ; get color under cursor
+        bra     @L2
+
+@L1:    stz     VERA::CTRL      ; use port 0
         lda     CURS_Y
         sta     VERA::ADDR+1    ; set row number
         stz     VERA::ADDR+2
@@ -21,7 +28,7 @@ _cpeekcolor:
         sec                     ; color attribute is second byte
         rol     a
         sta     VERA::ADDR
-        lda     VERA::DATA0     ; get color
-        plp
+        lda     VERA::DATA0     ; get color of character
+@L2:    plp
         ldx     #>$0000
         rts