Seeing all your hardware specs?

[mikeymike]

When I start Workbench, it says 9100000 bytes free (or I must be so stupid to mis see a zero...)

I think you're accidentally adding a zero :-)  Because IIRC (and my memory is a bit blurry on this one) that's the average amount of RAM you'd have left after WB has loaded on a stock A500 + half meg expansion.

[mikeymike]

1.5 Meg I think.

With a GARY chip hack.

(wrt 1.5MB FAST through the trapdoor)