Created a target and a library for the Commander X16 prototype computer.

libsrc/cx16/cpeekrevers.s

@@ -0,0 +1,32 @@
+;
+; 2016-02-28, Groepaz
+; 2019-09-25, Greg King
+;
+; unsigned char cpeekrevers (void);
+; /* Return the reverse attribute from the current cursor position.
+; ** If the character is reversed, then return 1; return 0 otherwise.
+; */
+;
+
+        .export         _cpeekrevers
+
+        .include        "cx16.inc"
+
+
+_cpeekrevers:
+        php
+        sei                     ; don't let cursor blinking interfere
+        stz     VERA::CTRL      ; use port 0
+        lda     CURS_Y
+        sta     VERA::ADDR+1    ; set row number
+        stz     VERA::ADDR+2
+        lda     CURS_X          ; get character column
+        asl     a
+        sta     VERA::ADDR
+        lda     VERA::DATA0     ; get screen code
+        plp
+        and     #%10000000      ; get reverse bit
+        asl     a
+        tax                     ; ldx #>$0000
+        rol     a               ; return boolean value
+        rts