Warning

You're browsing the old v2.x documentation. This version is no longer maintained. Click here to go the v3.x documentation.

Differences

This shows you the differences between two versions of the page.

--- extensions_tutorial [2019/12/12 11:10] – [Referencing XC=BASIC symbols in assembly language] neils
+++ extensions_tutorial [2019/12/12 11:36] – [Referencing XC=BASIC symbols in assembly language] neils
@@ Line 70: / Line 70: @@
   fun joy_firepressed!(port!)
-    rem -- we start
+    dim result!
     asm "
+      ; This is how to refer to a function's argument
+      lda {self}.port
+      ; Port #2 becomes 0, Port #1 remains 1
+      ora #%00000001
+      tax
+      ; This is how to refer to a global constant
+      lda _JOY_PORT2, x
+      ora #%00001000
+      eor #%00001000
+      lsr
+      lsr
+      lsr
+      ; A now holds the return value of our function
+      ; Write it to the variable "result!"
+      sta {self}.result
     "
+    return result!
   endfun