ajp166 at bellatlantic.net
Sun Apr 27 14:41:49 CDT 2008
>Subject: RE: 8251 troubles
> From: "Chuck Guzis" <cclist at sydex.com>
> Date: Sun, 27 Apr 2008 11:12:06 -0700
> To: cctalk at classiccmp.org
>Date: Sun, 27 Apr 2008 08:23:09 -0700
>From: dwight elvey <dkelvey at hotmail.com>
>I'm going to assume that you have an 8251A, not an 8251. If the
>latter, either sell it to a collector or have it bronzed and made
>into a tieclasp. There are substantial differences between the -A
>and non-A parts, all annoying.
I have both in quantity. Generally it's the quirks of the
"improved part"that are annoying but for simple Async serial IO
they are identical enough.
>The implication is that since the command register's write-only, you
>have to remember the last command you sent if you want to reset the
>error flag. One of the minor annoyances of a few early Intel
Yep, helps to have a table of set up variables.
>Anent that last one--make certain that your handshake lines
>(RTS/CTS/DTR) are set to the proper levels--an inactive CTS will
>prevent the 8251A from transmitting.
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