A500+ vs. MaxiMem memory upgrade

[fafler]

I have a A500+ REV 8A with 8375 Agnus and a Amitech MaxiMem memory upgrade. Giving a total of 1.5 MB ChipRAM. The MaxiMem originally came with a Gary adapter allowing the the board to take up to 2 MB, but don't have that adapter. I have filled the board with 44256-7 chips, but i can't figure out how to make the Gary "see" the rest.

My SCSI controller provides up to 8 MB FastRAM, so i want to map 1 MB of ChipRAM to 100000h to 1FFFFFh (assuming the onboard RAM is mapped at 000000h 0FFFFFh) and, if it's possible, 1 MB in the C00000h - CFFFFFh area.

BTW. whats the memory at C00000h - D7FFFFh called? And what can it be used for?

[hppacito]

Memory at 0xC00000..0xcfffff is autodetected by the kickstart without the need of addmem programs. It is "so-so-fast mem" refreshed by the gary suposedly, but can be implemented some other way, and has higher priority than chip mem for allocation purposes. I don't know if your fastRAM will have higher priority or similar, though. The use ?, similar to fastmem.
When you only have 1,5MB Chip mem:
The additional 1M chip mem, should be mapped to 0x08 0000 to 0x17ffff, to form a contiguos 1,5MB area. otherwise, you will have a hole between the end of the first 512k and the beggining of the 1MB.
For 2MB Chip... the extra 1MB should be mapped to 0x100000.
With that much Fast mem I don't see a need to map the extra chip at 0xC00000, more chip mem should be more advantageous.

[fafler]

The 1.5 MB ChipRAM i have now, is 1 MB onboard the A500+ and 0.5 MB on the expansion. I want to map 1 MB (or more, if possible) to ChipRAM. But if the C00000h area works works as FastRAM, you're right. It's not worth the effort.