cht@eddie.mit.edu (Chester Liu) (03/09/90)
Hi, I am on the verge of buying a MacIIcx color system with Apple's 13" RGB monitor. Having future upgrades and expansion in mind, I don't want to buy Apple's 8-bit board because it cannot be upgraded to any future 24-bit boards. What experiences do you have to a third-party 8 or 24 bit board? The RasterOps Colorboard 208, which is upgradeable to 264, sounds very attractive. Do other companies offer such a card and how slow really is a 24-bit card without a QuickDraw accelerator? Thank your for your valuable opinions, Chester Liu p.s. responses will be summarized. cht@athena.mit.edu uunet.uu.net, ihnp4!athena.mit.edu.cht ...!eddie.mit.edu!cht
vita@daredevil.crd.ge.com (Mark F Vita) (03/10/90)
In article <1990Mar9.004044.16761@eddie.mit.edu> cht@athena.mit.edu (Chester Liu) writes: >Hi, > I am on the verge of buying a MacIIcx color system with >Apple's 13" RGB monitor. Having future upgrades and expansion >in mind, I don't want to buy Apple's 8-bit board because it >cannot be upgraded to any future 24-bit boards. Wait a couple of weeks. According to MacWEEK, on March 19, Apple will rolling out (in addition to the IIfx) three new video cards to replace the current cards. There'll be a 4*8 card (i.e., 4 bits upgradeable to 8), a 8*24 card (8 bits upgradeable to 24), and a 8*24 CG (8 bits upgradeable to 24, with AMD 29000 QuickDraw accelerator). According to the story, all three new cards will drive all of the Apple displays. I suppose this means you could do 24-bit grayscale on the big Apple two-page display. I wonder how long it will be until Apple comes out with a Apple-labeled 19-inch color Trinitron display... -- Mark Vita vita@crd.ge.com General Electric CRD ..!uunet!crd.ge.com!vita Schenectady, NY
Fabian@cup.portal.com (Fabian Fabe Ramirez) (03/13/90)
Mark, "...24 bit greyscale..." Not quite. You need a color monitor for 24-bit color information, there is no greyscale for 24-bit mode as there is for 8-bit mode. Fabian Ramirez SuperMac Technology fabian@cup.portal.com sun!cup.portal.com!fabian
sands@apple.com (Michael Sands) (03/21/90)
It would not be possible to have 24-bit grey scale where you have full resolution in grey levels. But there is another way of looking at it. If you drive the red, blue and green guns equally, you have a black and white picture. If you then strive for as much resolution as possible, you will have 256 levels. This is the same as you currently have on a "standard" black and white monitor. The other question is how much resolution do you need to stimulate the typical human eye. A short poll here suggested anywhere between eight and ten bits. There are ten bit DAC's available. Michael Sands system extension group (408) 974-6108 novice driver, just my thoughts
fozzard@boulder.Colorado.EDU (Richard Fozzard) (03/22/90)
In article <7289@goofy.Apple.COM> sands@apple.com (Michael Sands) writes: >The other question is how much resolution do you need to stimulate the >typical human eye. A short poll here suggested anywhere between eight and >ten bits. There are ten bit DAC's available. > I used to work for an image processing company where we did some studies indicating that people could not see more than 64-128 levels [6-7bits]. 256 levels should be more than adequate for any grey scale images. The advantages of going to 10 or 12 bit images is the additional processing [ie. edge enhancement, etc] that can be done w/o loss of information. There is no reason to spend the money on 10 bit DACs to your monitor, but there is often justification to use 10 or 12 bit ADCs on input. rich ======================================================================== Richard Fozzard "Serendipity empowers" Univ of Colorado/CIRES/NOAA R/E/FS 325 Broadway, Boulder, CO 80303 fozzard@boulder.colorado.edu (303)497-6011 or 444-3168
isr@rodan.acs.syr.edu ( ISR group account) (03/22/90)
By using all three (RGB) DACs, carefully choosing the individual levels, and sending the outputs through a attenuator/mixing network, it is possible to acheive 12-bit accuracy in 16 stepped ranges. (ie, at the hi-order 4 bit bit transitions, there are mismatchs). -- Mike Schechter, Computer Engineer,Institute Sensory Research, Syracuse Univ. InterNet: isr@rodan.acs.syr.edu Bitnet: SENSORY@SUNRISE