Mail Archives: djgpp/1999/01/06/10:02:12.2
bowman wrote:
> Eric Rudd wrote:
> > timer routine failed similarly, I have concluded that Win95 (in its infinite
> > wisdom) is periodically tampering with the 8254, so I gave up on uclock(),
>
> How were you attempting to read the 8254? It has been a while since I've
> played with it, but my impression was if you use inport*(), Windows32 is
> only allowing you access to a virtual 8254, with very little effort
> given to maintain in in sync.
That would explain a lot. My old routine was written before I ever heard of DJGPP;
it was in Turbo Assembler, and used "in" and "out" instructions.
> There is a decent timer in the mmsystem package, but this is assuming
> you are building a windows app.
At home I'm not even running Windows, so I'd have to do more work to check if
Windows was running. Actually, I don't have a problem myself, since I'm pretty
satisfied with my RDTSC routines, but there was some discussion in this thread about
using uclock() to get 840-ns resolution, and I wanted to point out that one can't
expect such resolution under Windows.
-Eric Rudd
rudd AT cyberoptics DOT com
- Raw text -