[CCTALK] Commodore 1541 Drive

From: Cameron Kaiser <spectre_at_stockholm.ptloma.edu>
Date: Fri May 17 11:16:20 2002

> > That being said, you'd have to resort to driving the 6522s yourself to
> > manipulate the bitstream directly -- very low-level, and of course with the
> > small amount of RAM in the 1541 this would require impressively tight code.
> > But it is, theoretically, possible at least on some level, even if it's
> > merely decoding the bytes and handing them off to the C64 for processing
> > (putting the "DOS" in the 64).
>
> Programming 6522's is not that difficult (I've done it before and I'm
> working on a project right now that uses one). Isn't there 4K of RAM
> inside each 1541? That's a goodly amount of RAM for disk drivers.

2K, actually, and some of that space is microprocessor stack and various
work areas for the ROM routines for the FDC's tasks, some of which you
would probably want to use for space reasons. The safest place is in the
buffers from $0300-$07ff, which is only 1.25K.

-- 
----------------------------- personal page: http://www.armory.com/~spectre/ --
 Cameron Kaiser, Point Loma Nazarene University * ckaiser_at_stockholm.ptloma.edu
-- To err is human -- to forgive is not company policy. -----------------------
Received on Fri May 17 2002 - 11:16:20 BST

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:35:16 BST