Use unused address space in the Amiga 500 as RAM?

[freqmax]

The Amiga 500 have several patches of memory spread around in the memory map. Located at the positions:

0x00A0 1984 kB
0x00D8 256 kB
0x00DD 188 kB
0x00E0 512 kB
0x00E9 448 kB

This is 3388 kB of unused memory space. Provided RAM is present in those locations. Is it possible to make Kickstart/AmigaOS to use these locations as ordinary Fast RAM ?, or will using it use more RAM than is made available?

This should apply to other Amiga models too.

[joekster]

The icd adram does make use of some of those areas. I've always thought of putting together a max ram a500: 2mb chip, 8mb fast, 1.25(or so) from adram : total of 11.25mb in an a500

[Zac67]

Is it possible to make Kickstart/AmigaOS to use these locations as ordinary Fast RAM ?, or will using it use more RAM than is made available?

Sure, use AddMem as with any non-autoconfig memory.

[psxphill]

The icd adram does make use of some of those areas. I've always thought of putting together a max ram a500: 2mb chip, 8mb fast, 1.25(or so) from adram : total of 11.25mb in an a500

I had 2mb chip, 2mb fast & 1.5mb slow back in the day.
 
The 2mb chip ram upgrade I had didn't use any trapdoor or motherboard ram. Alot of them only have 1mb and you then you lose out on some slow ram.

[freqmax]

With Minimig and FPGA Arcade it possible to exploit every bit of memory space. But it requires well.. AddMem

I did not mention the possible 2 MB chip ram and another 512 kB or even 768 kB that can be used as RAM provided the ROM is small enough (hello AROS).