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Timing of 320x400 256c Tweaked VGA mode

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First post, by 7F20

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I need to create a resolution for my VGA monitor in Windows to properly display the tweaked 320x400 VGA mode because right now, it's just displaying it squished by half horizontally and full length.

Right now I've got this, but I'm not sure it's exactly correct. It's just what Custom Resolution Utility came up with using the "CRT Automatic" setting in the drop-down menu. I can't seem to find a good source for the timings of tweaked resolutions anywhere.

Thanks

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Reply 1 of 3, by Tiido

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This gives the low level timings to adapt : http://tinyvga.com/vga-timing/640x400@70Hz

Basically you halve the horizontal pixel values and also halve pixel clock to 12.5875MHz while leaving vertical line counts unchanged. That should give timings that are identical to 640x400@70Hz, at least to an analog display.

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
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Reply 2 of 3, by 7F20

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Ok thanks. That's basically what I figured it should be, and it's exactly what is shown in the CRU window other than the pixel clock and horizontal being a little off, but that's not entirely controllable with CRU, it only lets you adjust one of the three frequency fields and autofills the other two

Reply 3 of 3, by Tiido

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Pixel clock is critical however, it cannot differ.

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜

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