Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!crdgw1!uunet!ncrcom!usglnk!ncrlnk!ncratl!dscavo
From: dscavo@ncratl.AtlantaGA.NCR.COM (David Scavo)
Newsgroups: comp.dcom.modems
Subject: Re: UARTS and Buffers...
Message-ID: <18314@ncratl.AtlantaGA.NCR.COM>
Date: 3 Apr 91 13:10:06 GMT
References: <9104010808.AA05643@ucbvax.Berkeley.EDU>
Organization: NCR Engineering and Manufacturing Atlanta -- Atlanta, GA
Lines: 17

In <9104010808.AA05643@ucbvax.Berkeley.EDU> ST7021@SIUCVMB.BITNET writes:

>One last question - why doesn't the everyday serial port have a small buffer
>on it? It would seem that putting even a small buffer on the serial port
>would be a great relief to a CPU (espically one that is multi-tasking), as
>opposed to having to tend to an interrupt everytime a new character comes in.

That is what the 16550 is. It is a 16540 with a small buffer (I can not
remember exactly how big it is). The buffer is especially helpful when
doing 9600+ bps in a multitasking environment (Desqview, Windows, etc).
IF a buffered UART is not used when multitasking, characters are dropped
and the download usually aborts. Hope this helps.
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