Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!sun-barr!ccut!wnoc-tyo-news!astemgw!kuis!aegis!davidg
From: davidg%aegis.or.jp@kyoto-u.ac.jp (Dave McLane)
Newsgroups: comp.unix.sysv386
Subject: Re: Summary: 4-port cards
Message-ID: <2PBZ13w163w@aegis.or.jp>
Date: 24 Apr 91 22:47:36 GMT
References: <FW0P84N@geminix.in-berlin.de>
Organization: Aegis Society
Lines: 19

gemini@geminix.in-berlin.de (Uwe Doering) writes:

> I disagree. I developed FAS for NS16550A chips, and have six of them on my
> own serial card. And obviously, FAS uses the 16 byte FIFOs. The `AF' version
> has a faster timing, but is functionally equivalent to the `A' version. The
> trailing `N' indicates the packaging technique used for this chip, in
> this case a plastic body in DIL form.

I'm not sure how you know that "it's obvious that FAS uses the 16 byte
FIFOs." What indication did you get from FAS? 

The reason that I ask I am running FAS 2.0.8 with both NS16550AFN 
chips and the UARTs that are integrated with other functions on my 
Dell 333D; FAS accepts both and works with both ... until you see 
how much CPU time is being used. The significant reduction in time
would seem to indicate FAS is using the FIFO buffers in the
NS16550AFNs but not in the others....

--Dave