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Xref: sserve comp.sys.ibm.pc.hardware:33835 comp.unix.bsd:6781 Newsgroups: comp.sys.ibm.pc.hardware,comp.unix.bsd 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