Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!decwrl!ucbvax!unisoft!cander
From: cander@unisoft.UUCP (Charles Anderson)
Newsgroups: comp.unix.aux
Subject: Re: Keeping up with 19200 baud
Message-ID: <2659@unisoft.UUCP>
Date: 29 Nov 89 18:47:59 GMT
References: <74@van-bc.UUCP>
Lines: 17

From article <74@van-bc.UUCP>, by sl@van-bc.UUCP (Stuart Lynne):
> 
> Another data point, Appletalk (or whatever they are calling it these day's)
> run's at 240(?)kbps without problems.

I'm not sure how they (Apple) are doing it under A/UX 1.1.1, but MacOS
uses polled I/O to do LocalTalk at 240 Kbps.  This saves the interrupt
per character/100's of instructions overhead at the cost of essentially
shutting the machine down during transfers.  I believe this is the
reason that LocalTalk was not supported earlier using the motherboard
serial ports.  The hot ticket would have been if Apple had utilized the
DMA capabilities of the SCC chip, but alas...

-- 

Charles.
{sun, ucbvax, pyramid, uunet}!unisoft!cander