*BSD News Article 6732


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Path: sserve!manuel.anu.edu.au!munnari.oz.au!sgiblab!zaphod.mps.ohio-state.edu!wupost!csus.edu!netcom.com!hasty
From: hasty@netcom.com (Amancio Hasty Jr)
Subject: Re: Question on Diamond Clock Synthesizer
Message-ID: <1992Oct19.165341.14787@netcom.com>
Organization: Netcom - Online Communication Services  (408 241-9760 guest) 
References: <1b7tmgINNi06@agate.berkeley.edu> <1992Oct19.082420.16353@Informatik.TU-Muenchen.DE>
Date: Mon, 19 Oct 1992 16:53:41 GMT
Lines: 38

In article <1992Oct19.082420.16353@Informatik.TU-Muenchen.DE> roell@informatik.tu-muenchen.de (Thomas Roell) writes:
>>(1) Can Diamond's "programmable" clock synthesizers generate
>>_any_ frequency?  Could they thus be used to drive a fixed-scan
>>monitor?
>
>Yes, you can programm almost ANY frequency with that chip. There are a
>few limitations like the highest frequency the chip can produce
>(without emitting that neat smoke) and the resolution of the
>programming algorithm itself.
>
>>(2) Has anyone considered trying to reverse-engineer Diamond drivers
>>to discover the interface to the clock synthesizer?  It doesn't
>>seem like it'd be that hard.
>
>That won't help you that much. In the BIOS you'll find a list of
>values you can programm the PLL to which was considered useful by the
>BIOS writer (i.e. all frequencies you use for the BIOS modes). But it
>won't give you the information HOW to programm other frequencies. The
>next thing (and I belive that was Diamonds major reason not to pass
>the things away) is that there are more revisions of boards with more
>different PLLs than you moght believe. Should I really tell you that
>they all use the same basic chips, but have to be programmed a little
>bit different to get the desired results ? So what would happen if you
>programm the PLL wrong and blow your board ? Who is liable for this ? 
>
>- Thomas
>--
>-------------------------------------------------------------------------------
>Das Reh springt hoch, 				e-mail: roell@sgcs.com
>das Reh springt weit,				#include <sys/pizza.h>
>was soll es tun, es hat ja Zeit ...

Do you know of another manufacturer of svga who incorporates a
programmable clock synthetizer in their S3 card?


Amancio Hasty