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From: amichiel@rodan.acs.syr.edu (Allen J Michielsen)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: COM3/IRQ4
Keywords: IRQ4
Message-ID: <1991Feb16.035711.22145@rodan.acs.syr.edu>
Date: 16 Feb 91 03:57:11 GMT
References: <6820@rossignol.Princeton.EDU> <992@csource.oz.au> <59904@eerie.acsu.Buffalo.EDU>
Organization: Syracuse University, Syracuse, NY
Lines: 25

In article <59904@eerie.acsu.Buffalo.EDU> dmarcher@acsu.buffalo.edu (david m archer) writes:
>In article <992@csource.oz.au> david@csource.oz.au (david nugent) writes:
>>> If yes, then what is the use of having COM3 and COM4 ?
>>
>>Hanging different devices off each port.  You may not be able to use two
>>devices (on serial ports with the same IRQ) concurrently, but it sure
>>beats switching cables all the time. :-)
>
>I have an internal modem at COM3, and it's mere existance
>renders my COM1 as unusable, even if COM3 hasn't been
>accessed since power-up.   

   Cascading interrupts works well, and I do it all the time.  I have
nearly 100 pc's sharing int's concurrently, that work very very well.
However, The selection of your hardware is critical, and generally, you 
get just what you pay for.  The same can be said for some software which
when written poorly crashed randomly....
al



-- 
Al. Michielsen, Mechanical & Aerospace Engineering, Syracuse University
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