vault backup: 2022-08-01 10:10:54

content/notes/6809.md

@@ -7,10 +7,40 @@ tags:
 
 
 # Routines
+All variables are global so there is no params or local vars. 
+
+There are three way to "Branch" to a subroutine.
+- lbsr
+- bsr
+- jsr
+
+There are subtle differences but we will use bsr mostly
+
+```
+bsr myroutine:
+
+myroutine:
+	rts
+```
 
 # Iteration
+Done using GOTOs
+```
+	clra           //A = 0
+more:
+	cmpa #$06      //compare A to $06 (sets the equal flag in CC if true)
+	beq done       //if the equal flag is set, branch to done
+	inca           //increment a
+	bra more       //branch to more
+done:
+```
+
+other instructions set flags too
 
 # Input/Output
+![screen](https://i.imgur.com/IEiGKtj.png)
+
+
 
 # Hello World