Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!samsung!emory!gatech!prism!jgb
From: jgb@prism.gatech.EDU (James G. Baker)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: EISA vs ISA
Message-ID: <31927@hydra.gatech.EDU>
Date: 28 Jun 91 03:33:47 GMT
References: <1991Jun28.010434.24421@beach.csulb.edu>
Distribution: usa
Organization: Georgia Institute of Technology
Lines: 63

In article <1991Jun28.010434.24421@beach.csulb.edu> mosbrook@beach.csulb.edu (Brent Mosbrook) writes:
>
>I have been given the task of training some salesmen next week, and don't
>really want to re-invent the wheel.  Is there any good article/FAQ that anyone
>is aware of that will help me out in explaining the benefits of EISA?

I'm currently knee-deep in Micro Channel hardware development.  But, I've
read a lot about EISA.  One of the better "overview" magazine articles was
in PC Magazine (which I am losing respect for rapidly).  

Basically it said that the EISA designers who wanted to show Big Blue
that not everyone would jump off into MCA came up with a 32-bit bus
very similar to MCA.  (The xerox machine was probably still warm.) :-)

Both have:  	32-bit address and data
		Signals unique to each slot to activate and setup cards
		Allow cards to take control of bus more than DMA did in AT
		An extensive "setup" and CMOS configuration.

vs ISA:		16-bit data, 24-bit address
		pseudo 32-bit slots for 386 machines but every
		  manufacturer has its own proprietary "32-bit" slot
		  for memory, etc.

BUT, EISA slots can use ISA cards! true EISA cards slip down into
the slots via a key-notch in the card.  The setup tells the motherboard
which slots are 8-, 16-, and EISA.  I haven't heard of any compatibility
problems.  I think everyone is still waiting to see if MCA really 
becomes a standard in IBM's line.   Or if EISA will win because of the
ten-zillion cards out there for ISA.  A lot of companies make EISA
computers - Compaq, Dell, ALR, and others.  

EISA adapters are slowly creeping out - such as "Bus master EISA 
disk controllers".  But still a lot of $$$ for people that might
like ISA just as well.

Hope this helps...




>I have been given the task of training some salesmen next week, and don't
>really want to re-invent the wheel.  Is there any good article/FAQ that anyone
>is aware of that will help me out in explaining the benefits of EISA?  I have
>seen some very good, concise files posted here about modems, and thought that
>something like that is just what I need.
>
>
>Thanks for any and all info you can provide!
>
>
>-- 
>+--------------------------------------+
>|  Brent Mosbrook    KC6MWK            |
>|         mosbrook@beach.csulb.edu     |
>+--------------------------------------+


-- 
BAKER,JAMES G - Undergraduate Lab Instructor, School of Electrical Engineering
____  _    _    Georgia Institute of Technology, Atlanta Georgia, 30332
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