[comp.sys.ibm.pc] EISA bus.

grabhorn@marlin.NOSC.MIL (Steven W. Grabhorn) (10/11/88)

     A  week  or two  ago  several netters  wanted  to know  what 
information  was  available concerning the new  EISA  "standard". 
Since  I haven't seen too much factual info on the net  yet,  I'm 
posting  this  article  gleaned from the AST  bulletin  board  in 
Irvine, CA. [Which doesn't say a whole lot either :^)]

(I've deleted several direct references to AST's smartslot archi-
tecture.)
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EISA (Extended Industry Standard Architecture)

     "AST is a co-developer of EISA. The final technical spec  is 
still  being defined and AST is providing a great deal  of  input 
into it. The formal EISA slot design has not been finalized  yet, 
but EISA is a new architecture that will require a different  set 
of  connectors  from  AST's SMARTslot.  The  SMARTslot  and  EISA 
architectures are different in that SMARTslot is a 16-bit  design 
with  support  for multiple bus masters which  is  shipping  now, 
while  EISA  is  a 32-bit design with support  for  multiple  bus 
masters,  automatic configuration, and other features which  will 
be needed in the 1990s. 

     The  SMARTslot, Micro Channel, and EISA  architectures  also 
have some important things in common  - they are all for high-end 
multi-user systems and advanced file servers running new types of 
demanding  PC applications, such as workgroup computing.  Systems 
using EISA architecture will not be out until late 1989, but  AST 
is going to be a very strong supporter of the EISA standard.  The 
most  important thing about both SMARTslot and EISA is that  they 
are  AT compatible. There is no user benefit in any new  I/O  bus 
architecture for Intel-based PC's that justifies being incompati-
ble with the AT bus."

            QUESTIONS AND ANSWERS ABOUT AST AND EISA

Q: Did AST contribute to the development of EISA? To what extent?

A:  AST is a co-developer of EISA and has had  substantial  input 
into the functional specification. However, EISA is the result of 
a  cooperative effort involving several major  Personal  Computer 
manufacturers and independent hardware developers. No one company 
had a predominant role.

Q: How does EISA compare to AST's SMARTslot architecture?

A:  EISA and AST's SMARTslot architecture are similar. Here is  a 
summary of two of the main technical distinctions:

     - The  SMARTslot architecture is 16-bit, usable  in  systems 
       based  on the 80286, 80386 (and above)  Intel  processors. 
       EISA  is 32-bit, usable in 80386-based systems and  above, 
       such as 80486.

     - EISA  includes  some  supplementary  features  similar  to        
       those  provided  on IBM's Micro  Channel  which  SMARTslot        
       does  not. An example is the EISA automatic  configuration 
       capability,  which is similar to the  Programmable  Option 
       Select feature of the Micro Channel for identification and 
       automatic configuration of add-in boards.

Q: When does AST plan to deliver an EISA-based product?

A:  We are currently evaluating the EISA situation from an  engi-
neering  and  marketing standpoint. It is important  to  remember 
that even basic logic chips for the EISA architecture will not be 
available  for some time. It is possible that a product could  be 
delivered  sometime  during  late 1989, but we  have  no  planned 
target dates at this time.

AST Research
September 19, 1988
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As usual, these remarks and comments (except for AST's) are  mine 
alone.

Steve Grabhorn
grabhorn@nosc.mil

fverduin@neabbs.UUCP (FRANS VERDUIN) (07/15/89)

Ravi,
 
For mechanical specifications of the EISABUS connector you can 
contact Burndy Corporation in Norwalk CT.
For the description of the bus structure I am looking as hard as 
you do!  
 
Frans Verduin
Netherlands - Europe