Will's ATI Mach64 ISA page

This page details what I did to get the XFree86 3.1.2 Mach64 X servers to work with my ATI Graphics Xpression accelerated video card. I obtained the information from the USENET newsgroup comp.os.linux.x and the kind-hearted souls who posted the information I needed. From reading the newsgroup, I see many people are having the same problem that I had, but there seems to be no WEB page outlining the procedure, thus requiring the same information be posted over and over. My hope is that this page will cut down on some of the repetitive postings.

I offer this information and code on an "AS IS" basis with no warranty of any kind. The implied warranties of merchantablility and fitness for a particular purpose are specifically disclaimed. I will not be responsible for damages of any kind, including actual, incidental, or consequential damages. In other words, I hope this information helps you, but if it fries your monitor, video card, or any other item of property, I'll cry for you, but that's it.
NOTE: I have upgraded to 16MB of RAM since I first wrote this page, and so I can no longer use the XFree86 Mach64 X server. I have patiently waited for the folks at XFree86 to put out a Mach64 server that does not require a memory aperture, but I feel that this server will be vaporware for the foreseeable future. Accordingly, I have bailed out and ordered AcceleratedX. I may update this page from time to time, but because I will most likely not be using any future versions of the XFree86 Mach64 X server, my motivation to keep this page up to date is no longer present.
According to my best information, the XFree86 Mach64 X server requires the presence of a memory apeture. Enabling the memory apeture and configuring the XF86Config file appropriately appears to be the main hangup for folks trying to get their ISA Mach64 cards to work with the Mach64 X Server. From what I understand, the developers are working on a version of the server that will not require a memory apeture, so with any luck, this page will be obsolete before long. There is a commercial Mach64 X server called AcceleratedX from XInside for $99 that does not require a memory apeture, so you may want to check into obtaining it if you have the cash and you don't want to fiddle with enabling the memory apeture on the card or you have more than 8MB of RAM.

If you have more than 12MB of RAM, forget trying to get the XFree86 Mach64 server to work. The apeture must be mapped into an area below 16MB for the ISA version of the card, and that area cannot conflict with physical RAM. If you have more than 12MB of RAM, you are stuck with the SVGA server or you need to get AcceleratedX.

Ok, here's the procedure:

If all goes well, X Windows and your favorite window manager should come up. On my system, I had to adjust the horizontal centering knob to center the screen somewhat annoying, but tollerable).

I run X Windows with a resolution of 1024x768, which has proven to be very stable. 800x600 does not display on my screen at all, but 640x480 does. The color scheme when I invoked any of the Beta version of the server in 8 bit mode is not correct. All colors are false. The color scheme is correct if you invoke the server in 16 bit mode.

If you invoke X Windows with just startx, you only get 256 colors (8 bpp). To get 64k colors (16 bpp), invoke X as follows:
# startx -- -bpp 16
If the screen is off center with normal monitor settings, then you will need to adjust the clock timing parameters in your XF86Config file. Consult The Hitchhiker's Guide to X386/XFree86 Video Timing for detailed instructions on how to accomplish this.

I have not tried 32 bpp as my ATI card has only 2MB of VRAM and I prefer a resolution of 1024x768; a color depth of 16 bits is acceptable for me.

I sincerely hope this page helps people get the Mach64 server running with their ISA ATI Mach64 cards. I certainly had a hard time getting it to work, but the effort was worth it (the SVGA server is soooooooo slooow!).

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J. William Snyder, Jr. ()
Last modified: May 20, 2005

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