ScreenTest was developed to test the flaws present in the active matrix screens on the Powerbook 170, 180 and 180c computers (it will also work on the Duo 250 and 270c when they begin selling). Most active matrix screens come with some flaws. For the color active matrix screens they are either a stuck on or stuck off red, green or blue pixel. To test for a stuck off red pixel, you simply turn the screen all red and look for a black void. To test for a stuck off blue pixel, you simply turn the screen all blue and look for a black void. Same for green. To test for a stuck on red pixel you turn the screen all black and look for a red dot. Ditto for green and blue. Sounds simple doesn't it. Have you ever tried to do this? It is easy to turn the desktop all red (via the general controls panel), however, the menu bar is another story... Hence ScreenTest RGB.
Operation
Launch the program by double-clicking on the ScreenTest RGB icon or click on the icon and select File - Open from the Finder menu. Your monitor with the menu bar will be filled with a black screen and the cursor shape will change to a cross hair.
To mark a pixel as bad, position the cursor over the bad pixel and press the space bar. This will record the location for a print out later on during program execution.
To see which pixels you have marked as bad, press and hold down the option key. Each bad pixel on which you have marked will be outlined with a box. Release the option key to make the rectangles disappear.
If you marked a wrong pixel, you can delete your marks one by one by pressing the delete key.
If you want to clear all marked pixels then press the clear key.
Click the mouse button to move on. The monitor will now be filled with a red screen. Repeat the process for marking the bad pixels.
Click the mouse button to move on. The monitor will now be filled with a green screen. Repeat the process for marking the bad pixels.
Click the mouse button to move on. The monitor will now be filled with a blue screen. Repeat the process for marking the bad pixels.
Click the mouse button to move on. The monitor will now be filled with a white screen. Repeat the process for marking the bad pixels.
Click the mouse button to move on. The monitor will now be filled with a shareware fee plea screen. This is your last chance to make any corrections to your marked bad pixel list.
Click the mouse button to move on. You will now be prompted for a file name and location to save your marked bad pixel list to. Click Cancel to skip the report. Click Save to save the report. Your marked pixels will now be listed in the order in which they were selected, giving location and the color of the screen on which they were selected.
Remarks
I wrote ScreenTest to evaulate Powerbook screens for the purchase of a used Powerbook. It can also be used to make sure that your brand new Powerbook has as few flaws as possible. Or you could use it periodically to see if you qualify for a warranteed repair (five stuck off, or one stuck on).
Registration
If you feel obligated to reward me for sharing ScreenTest with the general public, then send $5 to:
KC Software
1179 Lilac Street
Broomfield, CO 80020
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