Hi bigmac,
You want the
Official A-Max Home Page.
The downloads are the ZIP files about half way down the page. They are all cracked versions which do not require either the A-Max cartridge or expansion card.
Note that the files are actually DMS disk images, not ZIP archives, so they should be renamed after you have downloaded them.
Incidentally, there is an active
A-Max disks thread here on EAB too.