Subject: Re: Release goo for 1.4.2_ALPHA
To: None <rh@vip.at>
From: Guy Morrogh <guy@anvil.co.uk>
List: port-i386
Date: 02/05/2000 18:46:59
Nah.

You're thinking of MCA (Micro-channel Architecture), which was a 32-bit 
system-independent bus launched with the PS/2. Not particularly 
popular (except at IBM - it survived in their RS/6000 systems a long time)

EISA was intel develop (in association, I believe with Compaq) as 
an enhanced 32-bit version of the ISA bus. It had a dual height
edge connector whose top level was normal ISA, and the bottom level
was the EISA addons - another 16-bits etc.

It ran at 8MHz, but 32-bits giving a peak 32MB/sec bus transfer.
There is a chunk of NVRAM (after the normal system NVRAM I think)
in the EISA spec used to hold configuration information. Normally ypu
had to configure EISA cards via a dos utility.

Generally found in servers. 

Compaq had some interesting (non-standard?) additions to the protocol
in their early Proliants to support their smart-array cards.

guy

> Robert Kennedy wrote:
> 
> > machine with PCI and EISA. It's a 486 motherboard with PCI slots and
> > 16-bit ISA slots. What's the difference between ISA and EISA?
> 
>   No, EISA is not 16-bit ISA.  IBM invented EISA as a
> backward-compatible, but more advanced bus system.  However, it (esp.
> the cards) remained quite expensive and were never quite adopted by
> other vendors.
> 
>   Cheers
>       ,
>    Rene

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