ranting on serial I/O cards

Stuart Lynne sl at van-bc.UUCP
Sat Feb 24 07:35:35 AEST 1990


In article <90.25E55172 at csource.oz.au> david at csource.oz.au (david nugent) writes:
>In a message of <Feb 23 23:18>, Stuart Lynne writes:
>
> >On Xenix even using 16450's will work for one or two Trailblazers quite
> >nicely. On my system (25Mhz 386) I didn't really notice a tremendous load.
> >
> >With 16550's I have run three Trailblazers and three 2400 Hayes with little
> >loading and no character loss problems.
>
>
>Unless the serial driver is written specifically to handle and will enable the 16550's FIDO queues, then the CPU overhead is the same as for 16450, so you shouldn't notice any difference at all.  Running a 16550AN without it's FIFOs "disabled" (well, the FIFO's themselves are always enabled, except the IRQ trigger levels are set at 1) will however aleviate some character loss in itself, since the FIFO is still present, and receive overruns become more rare.

It was. To amplifify my above remarks:

	I have run two Trailblazers under Xenix with 16450's using 
	SCO's std serial driver ....

	I have run three Trailblazers and three 2400 Hayes under Xenix
	using my own serial driver with a HUB6 card with 6 16550's ...

	I have run two Trailblazers under Xenix with 16450's using 
	my own serial driver ....


-- 
Stuart.Lynne at wimsey.bc.ca ubc-cs!van-bc!sl 604-937-7532(voice) 604-939-4768(fax)



More information about the Comp.unix.i386 mailing list