From: rsrodger@wam.umd.edu (Yamanari)
Subject: Re: EISA/MCA *or* Local Bus? Which is better for multitasking?
Organization: University of Maryland, College Park
Date: Fri, 1 Jan 1993 18:22:14 GMT

In article <1993Jan1.172109.12026@midway.uchicago.edu> sip1@midway.uchicago.edu writes:
>IBM has stated numerous times it will be delivering a LocalBus/MCA
>dual architecture machine (or two :-)) in the near future.  It is not
>yet clear whether that LocalBus design will be VESA or Intel PCI, but
>it will be one of the two.


	Does anybody know what physical connector PCI will be using?
	VESA uses the same as MCA (well, 1/2 ISA, 1/2 MCA).


>I wouldn't exactly call MCA dead, by the way.  It has a far larger
>market share than EISA (with no sign of change there; perhaps the
>opposite, in fact), and it is part of the third (or second, depending
>on whose figures you believe) best selling workstation line (the IBM
>RS/6000).  It is available from third parties, notably NCR and Reply.


	But not many.  hopefully, new systems will be done right.  Like
	the Power PC.  But I wouldn't expect MCA to penetrate any further
	into the low end thanks to LB, since most users don't need/want
	anythingmore than HS video and HS storage.  That's all going
	to fit on a 3 slot LB system with a slot to spare.


>While I'm on this subject, LocalBus isn't the only new bus
>architecture vying for a place.  PCMCIA is also in the running, and
>you'll see machines from IBM (both desktop and notebook) with PCMCIA
>slots.  They each have a place.


	PCMCIA is having a few growing pains (standardization
	problems).  Anyways, it's not terribly better than the other
	offerings--and certainly not as good as some of them.  It's
	only advantage would be to allow easy transfer between 
	a notebook and a desktop machine--i.e. flash ram disks, 
	kittyhawks, whatever.  It is *extremely* unlikely that it will
	everbe more than a 1 or 2 slot luxury on a desktop system.  


>I should also mention that several vendors (IBM and Compaq, notably)
>have had "LocalBus" video adapters for some time.  By placing the
>video on the motherboard these manufacturers did not have to worry
>about AT bus limitations.  


	Not true.  Amstrad offered on-the-motherboard graphics
	as far back as 1984.  These integrated video motherboards
	offered little or no speed advantage over their ISA
	kin.  to be precise, in fact, these integrated displays
	WERE on the AT bus, just like integrated HD controllers
	used to be.  

	They were certainly not local bus by any stretch of the
	imagination, and even if they had been (they weren't) they 
	must have been pretty miserable designs:  no speed advantage,
	and they couldn't be upgraded when a newer standard came along.  
	In many cases, they couldn't even be disabled, meaning that 
	to upgrade the video you had to replace the motherboard
	with a standard ISA system.

	They were, essentially, lousy.



>(True LocalBus, of course, offers up to
>three slots, which means the video circuitry can be replaced and still
>stay local.)


	Having "slots" doesn't necessarily have anything to do with what 
	"local bus" really means.  

-- 
	Blaming "society" for your problems is like blaming clouds for rain.

         ---  boycott == censorship == closed mindedness == cowardice  ---
		   	     Pain teaches.
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