You guys just don't answer fully the question:
- Local FAST RAM on accelerators: Up to 128Mb, pending the model. Some very old accelerators put the memory addressing inside the Zorro2 space, limiting the total amount of FAST RAM you can have on a system.
This was omitted because the OP said without an accelerator.
In the old days you had to put fast ram within the first 16mb, or devices with dma would get upset. It was only later that commodore allowed you to allocate memory where the address would fit in 24bits.
Annoyingly with an accelerator with local ram in the zorro 3 space, your zorro 2 dma is going to have to use chip ram. Unless you also have some zorro 2 fast ram.