Category Archives: CoCo Programming

CoCo (6809) Assembly on a modern computer

This article is a guide for anyone who is thinking about learning 6809 assembly language programming or wants to use newer tools for doing 6809 assembly for the Tandy Color Computer.  It’s not an assembly tutorial, it’s an explanation of … Continue reading

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Zilog z80 to Motorola 6809 Transcode – Part 023 – Optimized sprite rendering, combining Compiled sprites with Stack Blasting

Talking with other CoCo users about optimizing the sprite rendering on the CoCo I’ve figured out the best way to render the sprites for Pac Man on the CoCo3.  This article will summarize what I’ve learned and then explain what … Continue reading

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Zilog z80 to Motorola 6809 Transcode – Part 022 – Quick and dirty Speed Test – Five Sprites and 2 audio samples at the same time

I decided to put the Pac Man Sprite code and audio code together and see how fast the Pac Man transcode could be drawing five compiled sprites and playing back two separate audio samples at the same time.  There’s still … Continue reading

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Zilog z80 to Motorola 6809 Transcode – Part 021 – Compiled Sprites are faster then Stack blasting!

Hello, after writing previous blogs on how great stack blasting is, I’ve recently found out about an even faster sprite rendering method called Compiled Sprites.  A few weeks ago I was watching a CoCo youtube video and just briefly they … Continue reading

Posted in CoCo Programming | 4 Comments

Zilog z80 to Motorola 6809 Transcode – Part 020 – Sound ideas

I’ve taken a break from optimizing the Pac Man code to do some experiments with getting the CoCo 3 to play audio.  This is something I’ve read about but have never coded myself before.  I guess mainly because it involved … Continue reading

Posted in CoCo Programming | 5 Comments

Zilog z80 to Motorola 6809 Transcode – Part 018 – Transcode is complete and a look at level 256

Hello again, I’ve transcoded all the Pac Man z80 code to the 6809 now, except for some audio related code which isn’t going to be used on the CoCo 3.  The game plays properly now.  The demo mode ghost movement … Continue reading

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Zilog z80 to Motorola 6809 Transcode – Part 016 – Attract modes are done

Just a little update to say that I’ve made some great progress on the Pac Man code, it runs through both game attract modes properly and loops endlessly, looking for someone to put a quarter in the machine. I found … Continue reading

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