On Thu, 2007-04-26 at 03:14 +0100, Ensor wrote:
  Hi,
  Repair was usually a new floppy, new FDC and new
sound chip. Why
the sound chip?  Well... no, someone else can tell it. 
 I dimly recall that Atari used one or two signals from the I/O port on the
 sound chip as part of the disc interface - drive/side select? 
Coorrrrrrect!  See if you can guess how long it took to figure that one
out without the service manual...
Incidentally, a friend of mine ran a BBS for a couple of years on a
dual-floppy PPC640.  I think we ran it off a PC1640 monitor at least
once...
Gordon