Booting? Interrupts? What do I need to do?

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RivetRetro
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Booting? Interrupts? What do I need to do?

Post by RivetRetro » Thu Oct 01, 2020 6:08 am

Recently I got interested in tinkering with the Sega CD, and set out to start making a working image. Referencing docs and Luke's Bootloader I was able to get things like headers up and working. But after doing some reading through here I read that it's not the best example as it doesn't set certain Ints and the CD dies out after a little. Looking through some example sources I haven't really been able to figure out what I need to set or how and the closest thing to it that I could find in the docs was this and I have no idea what it's referencing with 0-FF:

Image

I've also heard talk about some area in MD ram around $FD00 and seen things in the cdbios.inc with values like $5F10 and don't quite know whats going on. Any help and explanations on what I need to do is appreciated :D

Miquel
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Re: Booting? Interrupts? What do I need to do?

Post by Miquel » Sun Oct 04, 2020 5:04 pm

RivetRetro wrote:
Thu Oct 01, 2020 6:08 am
I have no idea what it's referencing with 0-FF:
Both 68k read exception start address from the 8-255 first bytes memory address. Every 4bytes is a direct jump exception address.

Remember that when there is no cartridge the first two 4MB of address space on MD get swapped.
Help. Spanish TVs are brain washing people to be hostile to me.

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