Date: Thu, 14 Mar 2002 17:38:59 +0800 From: Raymond <[EMAIL PROTECTED]> Subject: Re: [LIB] Touchscreens for Librettos - alternatives
At 12:45 AM 14/03/2002 -0800, you wrote: >Date: Thu, 14 Mar 2002 08:40:07 >From: "neil barnes" <[EMAIL PROTECTED]> >Subject: Re: [LIB] Touchscreens for Librettos - alternatives > >>Date: Thu, 14 Mar 2002 09:39:53 +0800 >>From: Raymond <[EMAIL PROTECTED]> >>Subject: Re: [LIB] Touchscreens for Librettos - alternatives >> >>At 08:20 AM 13/03/2002 -0800, you wrote: >>>Date: Wed, 13 Mar 2002 16:11 +0000 >>>From: [EMAIL PROTECTED] >>>Subject: Re: [LIB] Touchscreens for Librettos - alternatives >>> >>>Hi, all, >>>other alternatives are light pens, to turn any display into a touchscreen system. >> >>Umm ... AFAIK light pens won't work on LCD displays because there is no raster to >key onto. > >That's my thought, too - they take a raster input but once the cell is switched it >stays there till the next refresh. LCDs by themselves don't take a raster input ... to plug an LCD into a raster source you need a converter (its just that most desktop LCDs have the converter built in) so you go from digital through the video card DAC, through the monitor cable to the ADC on the LCD then to (presumably) a little frame buffer on the LCD side (to match refreshes and the like) then to the LCD display, which (in the case of TFTs) refresh whole lines at a time. Thats why you're getting these video cards with digital out (sometimes called flat panel out), eliminating the analogue stage. - Raymond --- /~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\ | | "Does fuzzy logic tickle?" | | ___ | "My HDD has no reverse. How do I backup?" | | /__/ +-------------------------------------------| | / \ a y b o t | [EMAIL PROTECTED] | | | HTTP://www.raybot.net | | ICQ: 31756092 | Need help? Visit #Windows98 on DALNet! | \~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~/ ************************************************************** http://libretto.basiclink.com - Libretto mailing list http://libretto.basiclink.com/archive - Archives http://www.picante.com/~gtaylor/portable/faq.html - FAQ -------TO UNSUBSCRIBE------- Reply to any of the list messages. The reply mail should be addressed to: [EMAIL PROTECTED] - Then replace any text on the message's subject line: cmd:unsubscribe --------TO UNSUBSCRIBE DIGEST------ Do above but with this on subject line: cmd:unsubscribe digest **************************************************************
