From: P D H (pdh@netcom.com)
Date: 05/02/93


From: pdh@netcom.com (P D H)
Subject: Re: Can COM1/2: and COM3/4 be used simultaneously?
Date: Sun, 2 May 1993 06:00:32 GMT

Theodore Ts'o <tytso@athena.mit.edu> writes:

>The reason why the serial driver polls all of the serial ports on a
>particular IRQ is to support multi-port serial boards, which are
>*designed* to support 4, 8, or 16 serial ports using a single IRQ.
>These Linux will support fine --- as long as you get the interrupt to
>the serial driver, it should deal appropriately. Examples of multi-port
>serial boards which Linux will support include the AST Fourport (and its
>clones), the Usenet Serial Board II, and the Boca 4-port, 8-port, and
>16-port (BB-1004, BB-1008, and BB-2016).

You mean they actually designed these boards this way?

The design I would have done is one where a single poll can determin if
and where data is available. It could even give that data and which port
it was from with a 16-bit IN.

-- 
| Phil Howard,  pdh@netcom.com,  KA9WGN         Spell protection?  "1(911)A1" |
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