noidentity
Well-known member
I have been able to hack the built-in video driver of my PowerMac 8500 to support 1920x1080 and 1680x1050 LCD panels perfectly (been using 1920x1080 for over a month now with zero problems). The LCD is able to lock on to the pixel rate and phase so that each pixel is perfectly clear, no blurring or anything. The new resolution shows up normally in Monitors, and when selected and the machine restarted, it will properly switch to the new resolution part way through the boot screen.
I've also done the same for the IX-Micro PCI video card that the PowerMac 9600 and some others used. This will probably also work on all PowerMac models using the same video circuitry: 7300, 7500, 7600, 8500, and 8600 (maybe someone can post a definitive list of models using the same circuitry, in case I left some out). This is a software-only modification; no hardware changes needed.
Is there any interest in posting these, or does everyone use these older machines on smaller displays or with newer video cards? I've figured out how to adjust all the standard video parameters, allowing custom modes with other resolutions too. The parameters adjustable are pixel rate (e.g. 148.5 MHz), horizontal rate, refresh rate, front/back porch and sync width for horizontal and vertical, and of course the horizontal and vertical pixel size. There are no code changes, just adjustments of the timing values in the driver. There is also a choice of modifying the driver in the System file, or modifying a video driver extension. Also, adjustments can be made to parameters without restarting.
I've also done the same for the IX-Micro PCI video card that the PowerMac 9600 and some others used. This will probably also work on all PowerMac models using the same video circuitry: 7300, 7500, 7600, 8500, and 8600 (maybe someone can post a definitive list of models using the same circuitry, in case I left some out). This is a software-only modification; no hardware changes needed.
Is there any interest in posting these, or does everyone use these older machines on smaller displays or with newer video cards? I've figured out how to adjust all the standard video parameters, allowing custom modes with other resolutions too. The parameters adjustable are pixel rate (e.g. 148.5 MHz), horizontal rate, refresh rate, front/back porch and sync width for horizontal and vertical, and of course the horizontal and vertical pixel size. There are no code changes, just adjustments of the timing values in the driver. There is also a choice of modifying the driver in the System file, or modifying a video driver extension. Also, adjustments can be made to parameters without restarting.
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