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From: daveh@cbmvax.commodore.com (Dave Haynie)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: SRAM and BURST mode on 3000
Message-ID: <18888@cbmvax.commodore.com>
Date: 12 Feb 91 23:37:13 GMT
References: <1408@ewu.UUCP> <5665@mnetor.UUCP> <8332@ucdavis.ucdavis.edu> <18764@cbmvax.commodore.com> <1991Feb11.015011.621@medsys.uucp>
Reply-To: daveh@cbmvax.commodore.com (Dave Haynie)
Organization: Commodore, West Chester, PA
Lines: 35

In article <1991Feb11.015011.621@medsys.uucp> wendell@medsys.uucp (Wendell Dingus) writes:
>bryce@cbmvax.commodore.com (Bryce Nesbitt) writes:

>>In article <> dalbec@sakura.ucdavis.edu (Gabe Dalbec) writes:
>>>How do I turn on static colum mode and burst mode for my A3000.

>>The OS detects static column chips, and enables burst mode automatically.
>>There are several "turn on SCRAM" programs out there.  If they crash
>>your machine, you probably don't have properly working SCRAMs.

>Ok, why after a cold boot does SetRamsey tell me that burst mode is on, but
>static column, and Burst Wrap mode are off. I can turn them on and the 
>machine works fine, and gets a few points higher in most benchmarking
>programs with these modes on. Why don't they stay on? They seem to stay
>as set after a warm boot. 

They don't stay on because you don't want them on, probably.  The OS folks,
like Bryce, have done testing to find out which parameters, both in RAMSEY
and 68030 cache control, yield the best performance.  Not in the reasonably
silly benchmark programs around, but in actual test of representative code.
Even Dhrystone 2.x will show that page-detect mode (what SetRAMSEY calls
static column mode) is at best a draw, and sometimes a loss, in most programs.
Plus, it has a potential conflict with hard disk DMA.  Apparently, SetRAMSEY
was written early in the testing periods of the A3000, before the OS knew
the right things to do.  A proper utility would at least check the version of
the RAMSEY and refuse to set up page-detect mode in the current system.  Both
page-detect and burst modes in RAMSEY are static column memory modes.

>Wendell Dingus


-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
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	"What works for me might work for you"	-Jimmy Buffett