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On Thu, 6 Jun 1996, Elvin Tan wrote: > I have a 701C myself. Just wondering, they say the chipset can show 16m > color (as can be seen by the vesa or windows drivers) and the LCD can > do 256 colors. Does that mean the LCD pixels can do a certain no. of > colors only ? (Meaning a fixed 256 color ? Or a fixed 256 colors from > 16m color ? If it's fixed, anyone got the palette?) It depends. :) A red pixel on an LCD will show bright red by letting all light through. It will show no red by blocking all light. Any shade of red in between is accomplished by rapidly turning the pixel on and off to generate the illusion of a not-so-bright shade of red. How many "shades" it can show simultaneously and from what size palette depend on the hardware controling the LCD (different from the video hardware). I've seen all sorts: 512 colors, 256 colors from a palette of 4096, 4096 colors, 4096 simultaneous and 256 colors from a palette of 64k, etc. Testing my 701C's TFT side by side with a monitor, I've determined it can do no more than 32k colors simultaneously. However, a Thinkpad engineer said it could do 256k colors. My guess is that it can do 32k colors simultaneously, and 256 colors from a palette of 256k colors (18 bits per pixel, or 6 bits per primary - standard VGA palette). That is, if you put it in 256 color mode and showed shades of one primary, you'd get 2^6, or 64 shades. Whereas in 32k color simultaneous mode you can only do 2^5 or 32 shades. I have yet to test this. There are a couple web sites that covers LCDs in excruciating detail: http://cal003109.student.utwente.nl/stefan/el/misc/lcd_faq.htm http://itri.loyola.edu/Displays/C3_S3.htm -- John H. Kim There are only two industries that call their jokim@mit.edu customers 'users,' and one of them is illegal.