I think the 1772 is a generally improved version of the 1770, with new head stepo rates - I think the 1770 was 6ms, 12ms, 20ms, and 30ms, whereas the 1772 is 2ms, 3ms, 6ms and 12ms. Or something like that.
I think the 1770 and 1772 are pin compatible, but if you can't get hold of a 1772, then you ain't gonna get a 1770! When I've asked about tweaking the DOS for a new controller before, the response seems to have been that it is impossible.... but I can't believe it's too tricky for some dedicated hacker. Talking of the DOS, we've got both the ROMs and MASTERDOS source files on the ftp site... but not SAMDOS2. Any reason why not? Andy
