HP-48GX black and white screen: blue indicators?

[cyrille de brébisson]

Hello,

My understanding is that the screen (pixel area) is multiplexed. Each row/pixel only gets energized for 1/64 of the time. Bump up the contrast (which bumps up the voltage), especially past the software forced limit (by writing in the IO rom directly using the POKE command), and you will see that the screen pixels will become blue-er, which is their saturated color...

Now, the Indicators are NOT multiplexed, they are energized 100% of the time. So they show as the other pixels would if they were fully energized.

Cyrille.