---
title: "6809"
aliases: 
tags: 
- cosc204
---


# 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

# Assembler