Re: cyrix 6x86 and ne2000 driver problem

Nick Evgenev (
Wed, 7 May 1997 18:58:57 +0400 (MSD)


On Tue, 6 May 1997, Mike Jagdis wrote:

> > But in fact something working wrong :). As I wrote exchange
> > cyrix cpu on intel or isa ne2000 on amd pci has solved all my problems.
> > In a few days I will be able to test pci ne2000. If it will working
> > fine with cyrix, then the problem is isa delays. Are you agree? Should
> > I test other isa cards like 3com?
> The Cyrix CPUs have a configurable delay between I/O instructions
> which defaults to 32 *bus clock* cycles for the 6x86 (I think the
> 5x86 is the same). This should be sufficient for normal cases but
> it could be wrong if (a) the motherboard jumpers aren't set correctly
> and a smart BIOS tries to adjust the delay, (b) the BIOS knows
> about 6x86 I/O delays, allows you to configure it, and you get it
> wrong, (c) you have applied the latest cyrix patch and enabled
> the fast I/O option.
> In all these case there will *only* be a problem if the device
> driver does not include dummy I/O instructions or delay loops
> in *all* the necessary places.

I just played with set6x86... Disabling fast IO (i.e.
32/64 cycles) has no effect. :(