In article <44A1A111.5010808@black-star.demon.co.uk> you write:
>David Laight wrote:
>
>> Woudn't it be better to dereference a pointer to a volatile memory location
>> inside the loop - that way the compiler isn't allowed to optimise the
>> loop away.
>> 
>The volatile variables seem to be enough for now. Although I can see a 
>cleverer optimiser requiring the fix you propose.
>
>A better fix would be to actually use a hardware timer. If I can figure 
>out a way of doing that on acorn32 I'll see if I can fix the routine so 
>that it no longer depends on the delay loop at all.

It shouldn't be particularly painful to use the IOMD timer.  Fixing 
this, and using timecounters at the same time, are somewhere on my 
acorn32 TODO list, but they're a little below getting NBFS into a state 
where we can finally stop using UnixFS.

-- 
Ben Harris