Request of sample code for Mega CD scaling/rotation

I am developing a Sega CD test program (see this thread )
Is anyone willing to share (simple) sample code for scaling/rotation using the mega cd ?
I read the sega retro mega cd's hardware and development manuals, but the information is rather scarce.
On the other hand the code I found is only from huge projects.
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Ban Hammered
You need to tell us what system mode you're using (e.g. "system mode 1" or "system mode 2"), and what function. According to that link thread an Everdrive is being used which isn't exactly transparent; moreover it's being used on faulty hardware to develop the program... Unfortunately my mini howto is still alpha so doesn't explain how to start prepared.

Did you already replace capacitors on both the core and cd side?

You also need to explain what code system: snasm, codewarrior or something else...?
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I already replaced all the caps, logic/laser/power board.

As long as anybody has some code, I will adapt it. For the system mode, I can just define a constant and add it, as I did in
(see the OFFSET variable)

For the developing environment i use sgdk (g++ and gnu assembler) but I have no problems in adapting code from any other assembler
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