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Reduce streaking of Palm IIIx screen
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Some Palm IIIx displays have the 'streaking' problem. They tend to extend vertical lines (can be seen in the datebook month view) . Sometimes this can be adjusted by reducing the contrast using the contrast adjustment wheel.

This problem can sometimes be solved with software by changing the display refresh frequency. The PalmOS 3.1.1 upgrade and other programs cure this, but i wanted to have my own open source version. Here it is.

Flickering greyscale on the Palm IIIx and Handspring Visors

In order to prevent streaking, the PalmOS 3.1.1 upgrade and all later OS versions for the Palm IIIx and some old models of the Handspring Visor (not the prism or the platinum) reduce the screen refresh rate like this hack does.

Reducing the refresh rate has one major disadvantage: Greyscale pixels are generated by turning the pixels on and off very fast by the video controller. Together with the reduced screen refresh rate of the Palm IIIx and some Visors, this causes visible flicker in greyscale video modes used by some games and e.g. programs like AvantGo.

It is possible to setup nostreak to disable the anti-streaking code in these OS versions. In order to prevent flickering greyscale modes in e.g. programs like PalmBoy on the Palm IIIx and the Handspring Visor, install nostreak, start the hackmaster application, go to the nostreak setup (the small '+') and set the refresh rate to '0' and select 'enable in greyscale mode'. After that you might need to re-adjust the contrast setting, but the flickering in greyscale applications will be gone.

This disables the anti-streaking features of PalmOS and you might see streaking on your Palm IIIx or Visor after this. There is no way to reduce streaking and to avoid flickering greyscale at the same time.



  • Version 1.1 really works with greyscale
  • Version 1.2 allows to adjust the refresh rate on a 'streak demo page'
  • Version 1.3 can be activated for greyscale modes seperately

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