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From: kirsch@ux.acs.umn.edu (Dave Kirsch)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: EISA/ISA  What is the difference???
Message-ID: <2910@ux.acs.umn.edu>
Date: 15 Dec 90 03:14:47 GMT
References: <5908@yang.earlham.edu>
Reply-To: kirsch@ux.acs.umn.edu (Dave Kirsch)
Organization: University of Minnesota
Lines: 42

In article <5908@yang.earlham.edu> johnb@yang.earlham.edu writes:
>Can any one tell me the important differences between EISA and ISA busses.
>
>In particular, wont a 32-bit bus b important down the road?
>why not get a EISA bus?

  Yes, EISA is a 32-bit bus, and yes, a 32-bit bus will probably be important
at some point down the road. However (correct me if I'm wrong; I'm sure 
someone will), if you have an EISA system all expansion boards must be EISA 
boards or you will lose the functionality of all of them - assuming that at 
least on of your expansion boards is an EISA board. (i.e. You won't be able 
to have an EISA board and, say, an 8-bit game adapter card installed in 
the same system and have full functionality - if any.) 

  The main advantage *I* personally have seen in EISA systems over regular 
ISA systems is that bus-mastering is *far* more reliable. 

  My *personal* advice is to buy an ISA system if you just want an affordable 
yet very capable PC. If you want a 32-bit bus, buy a Microchannel machine. 
Before people start flaming me to death, listen up; I wouldn't even have 
thought of recommending this until a couple of months ago, when IBM opened up
the Microchannel standard. (i.e. They're not gonna hold people hostage if 
they want to build a Microchannel machine. IBM still has the final say on 
modifications to Microchannel, but people are no longer going to be ripped 
off for outrageous licensing fees in order to build a Microchannel machine.) 

  Note that this is only my opinion. I think ISA machines are more than 
enough for anything most people want to do these days. However, I also think 
that Microchannel is technically far superior to EISA. As long as IBM is no 
longer going to keep Microchannel 'proprietary', I think it's the way to go. 
 
>Any help is appreciated.
>
>John Benjamin
>johnb@earlham.bitnet

  Hope this helps a *little* bit. 

Dave Kirsch 
kirsch@ux.acs.umn.edu 
".. so, like, if you were in outer space and you blew your wad, would go on 
  for infinity"  - Billy in 'Patti Rocks'