Date   : Sun, 30 Oct 2005 00:24:43 +0100
From   : jgh@... (Jonathan Graham Harston)
Subject: Re: Programming the 8271 and 1770 FDC's from BASIC

Greg Cook <debounce@...> wrote:
> The problem is how to communicate which density to use -- an argument
> to *FORMAT normally provides it, so users of OSWORD &7F must do an
> extra command or sometimes a poke to set the density.  As usual, a
 
With DFSs that support it, the density is selcted with with b5 and
b4 of the drive number:
 
        XY+0    drive number %pxDDddsd
 
  p  : If 1, selects the previously-used drive and density
  DD : select the drive density:
       %0x=current density
       %10=FM
       %11=MFM
  ddd : physical drive number
  s   : side
 
Watford DDFS supports this, Acorn DFS doesn't. I don't know about
any other DFSs.
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
There are three food groups: brown, green and ice cream.