Tag Archives: 6809

Defender Conversion for the CoCo 3 – Part 6 – Three out of Three attract Screens are converted

Today I completed converting the Defender Arcade code to play through all three attract modes.  The last one was definitely the hardest as it contains the sprites moving around the screen.  I also had to convert how Defender draws the … Continue reading

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Defender Conversion for the CoCo 3 – Part 5 – Another cool 6809 coding trick they used

Hello, I just wanted to document this neat little trick here.  For changing the colour of one of the 16 stars on screen randomly in Defender they do the following: * Table of stars @ $AF9D to $AFDC * Format … Continue reading

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Optimizing 6809 Assembly Code: Part 4 – Odds and Sods – More Tricks

Table of Contents (click on a link to jump to that web page) Part 1 – Quick and Easy Changes to Speedup Your Code Part 2 – Speedup Storing Data – Unrolling Loops Part 3 – Stack Blasting and Self Modifying Code … Continue reading

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Optimizing 6809 Assembly Code: Part 3 – Stack Blasting and Self Modifying Code

Table of Contents (click on a link to jump to that web page) Part 1 – Quick and Easy Changes to Speedup Your Code Part 2 – Speedup Storing Data – Unrolling Loops Part 3 – Stack Blasting and Self Modifying Code … Continue reading

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Optimizing 6809 Assembly Code: Part 2 – Speedup Storing Data – Unrolling Loops

Table of Contents (click on a link to jump to that web page) Part 1 – Quick and Easy Changes to Speedup Your Code Part 2 – Speedup Storing Data – Unrolling Loops Part 3 – Stack Blasting and Self Modifying Code … Continue reading

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Optimizing 6809 Assembly Code: Part 1 – Quick and Easy Changes to Speedup Your Code

Table of Contents (click on a link to jump to that web page) Part 1 – Quick and Easy Changes to Speedup Your Code Part 2 – Speedup Storing Data – Unrolling Loops Part 3 – Stack Blasting and Self Modifying Code … Continue reading

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