Path: utzoo!attcan!uunet!snorkelwacker!spdcc!eli
From: eli@spdcc.COM (Steve Elias)
Newsgroups: comp.sys.ibm.pc
Subject: AMD 8237 feature
Message-ID: <782@ursa-major.SPDCC.COM>
Date: 4 Dec 89 00:01:37 GMT
References: <1247@adds.newyork.NCR.COM> <28150@amdcad.AMD.COM>
Reply-To: eli@ursa-major.spdcc.COM (Steve Elias)
Lines: 29

In article <28150@amdcad.AMD.COM> phil@diablo.AMD.COM (Phil Ngai) writes:
>The real story (although I am not an official spokesman) is that AMD
>did the first generation of the DMA controller and licensed the design
>to Intel who modified it a little and documented the enhancement. Boca
>Raton designed to the Intel data sheet and didn't check to see if it
>was downward compatible with AMD's design. It wasn't but until
>Fastback came along there was no software which exposed the problem.

	believe me, some of us were working on software back then
	that did expose the problem in a big way.  not an easy bug
	to find.  we couldn't afford an in circuit emulator for 8088,
	even if there was around that worked...

>Since then AMD has incorporated the Intel enhancement in their chips
>(it is a very simple change) and most motherboard makers use circuits
>which are compatible with both generations of DMA controllers. 

	what is the motherboard patch which precludes this bug?

>AT&T Unix System V.4: Berkeley Unix for 386 PCs!

	yeah!

	
-- 


-- Steve Elias ; eli@spdcc.com ; 6179325598 ; 5086717556 ; { *disclaimer(); }