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Received: by minnie.vk1xwt.ampr.org with NNTP id AA2283 ; Mon, 01 Mar 93 10:52:18 EST Path: sserve!manuel.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!agate!howland.reston.ans.net!paladin.american.edu!news.univie.ac.at!hp4at!mcsun!sun4nl!tuegate.tue.nl!rwa.urc.tue.nl!rcpt From: rcpt@rwa.urc.tue.nl (Piet Tutelaers) Newsgroups: comp.os.386bsd.questions Subject: Re: How to select 72MHz on ET4000 board? Message-ID: <rcpt.730720661@rwa.urc.tue.nl> Date: 26 Feb 93 09:57:41 GMT References: <rcpt.730581552@rwb.urc.tue.nl> <1993Feb25.151244.15114@gmd.de> Sender: root@tuegate.tue.nl Reply-To: rcpt@urc.tue.nl Lines: 34 veit@borneo.gmd.de (Holger Veit) writes: >In article <rcpt.730581552@rwb.urc.tue.nl>, rcpt@rwb.urc.tue.nl (Piet Tutelaers) writes: >|> >|> The ET4000 board in our 486DX33 box does provide a 72MHz clock in >|> order to achieve a 70 Hz refresh rate for 1024x768 mode. The manual >|> explains how to select this frequency with VMODE.EXE an MSDOS utility >|> (mode 0x38). >|> >|> If I startup `startx' and write its output into a file I don't see this >|> 72MHz clock. Does this mean I can't select this clock with XFree1.2? >The clock might be select with a mechanism that is not in the area >of the standard 16 clocks. This is not supported by XFree86. Another >possibility is that your VMODE (or the handbook) lies about the 72MHz; >also already seen. There is a facility to run an external clock >program (if you manage to find out how the 72MHz clock is enabled), >see the XFree86-1.2 doc on this. Thanks for this information. I see two solutions to the problem: buying another ET4000 board which supports a 75 MHz dot clock (this value is suggested by the standard VESA settings in Xconfig.sample) to get the 70 Hz refresh rate that is supported by XFree86-1.2 (but which one?); or digging into the nitty-gritty details of setting the external clock for the card we (and a lot of other people I expect) have. For the last solution I need some pointers into the good direction. Regarding the first solution: which ET4000 cards are supported by the stock XFree86-1.2 in VESA mode (70Hz at 1024x768: needed clockrate about 75 MHZ)? Or even better in 70-72Hz at 1252x900 (expected clock rate 100 MHz). Buying on the documentation provided with XFree86-1.2 (X386/lib/X11/etc/modeDB.txt) does not give any garantee that your card does match your monitor. --Piet