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From: gandrews@netcom.COM (Greg Andrews)
Newsgroups: comp.unix.sysv386
Subject: Re: Equinox and HFC
Summary: A minor technical point...
Message-ID: <25134@netcom.COM>
Date: 22 Feb 91 03:17:13 GMT
References: <394@icjapan.uucp>
Followup-To: comp.unix.sysv386
Organization: Netcom - Online Communication Services  UNIX System {408 241-9760 guest}
Lines: 32

In article <394@icjapan.uucp> Jim Dixon <dixon@info.com> writes:
>
>Various issues dealing with Equinox Megaport Hardware Flow Control,
>or the lack thereof.
>
>The following is a severe flamage...
>

Yikes!  I don't want to get in the way of your flamethrower, Jim, but
I'd like to comment on a techical point that you mention...

>    [flames about getting support on wiring issues deleted]
>      [more flames about CTSFLOW/RTSFLOW issues deleted]
>
>Wouldn't it be nice if the card supported CTS flow control by default.
>Regular serial ports that use UARTs and the like do it. Regardless
>of *WHAT* software you are using, if you drop CTS, the UART's transmitter
>will stop sending until you raise it again, independent of software control.

Uh...if you're talking about an 8250/16450/16550 uart chip on a standard
'non-intelligent' serial card, that's not the case.  The uart does no
flow control interpretation whatsoever.  It pays no attention to XON/XOFF
characters, and the only thing it does with CTS is turn a bit on/off in
one of its status registers.  If you feed the uart a character to transmit,
it will transmit that character whether CTS is up or down.  It's up to the
driver software to check the state of the control signals and take the
appropriate action (or inaction).

-- 
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| Greg Andrews      |   gandrews@netcom.COM |
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