gerhard@cs.arizona.edu (Gerhard Mehldau) (04/30/91)
Another question for all you hardware gurus out in NetLand:
The LC comes standard with 256K of Video RAM, which allows
me to run the Apple 12" monitor in 8-bit mode, and the 13"
monitor in 4-bit mode.
Apple (as well as some third-party vendors) also sell a
512K VRAM chip, that replaces the 256K chip and lets me
run the 12" monitor in 16-bit mode, and the 13" monitor
in 8-bit mode.
Now, does anyone know what is preventing Apple (or third
parties, for that matter) from making 1M or 2M VRAM chips,
that would allow me to run the 13" monitor in 16- or 32-bit
mode? Technology? Price? Also, would the LC be able to
take advantage of such chips, or are there some limitations
in the design of the machine that would prohibit this?
Inquiring mind wants to know...
- Gerhard
--
-> Gerhard Mehldau
Dept. of Computer Science internet: gerhard@cs.arizona.edu
University of Arizona uucp: {cmcl2,noao,uunet}!arizona!gerhard
Tucson, AZ 85721, U.S.A. voice: +1 (602) 621-4632hades@eleazar.dartmouth.edu (Hades) (05/01/91)
gerhard@cs.arizona.edu (Gerhard Mehldau) writes: >Another question for all you hardware gurus out in NetLand: >The LC comes standard with 256K of Video RAM, which allows >me to run the Apple 12" monitor in 8-bit mode, and the 13" >monitor in 4-bit mode. >Apple (as well as some third-party vendors) also sell a >512K VRAM chip, that replaces the 256K chip and lets me >run the 12" monitor in 16-bit mode, and the 13" monitor >in 8-bit mode. >Now, does anyone know what is preventing Apple (or third >parties, for that matter) from making 1M or 2M VRAM chips, >that would allow me to run the 13" monitor in 16- or 32-bit >mode? Technology? Price? Also, would the LC be able to >take advantage of such chips, or are there some limitations >in the design of the machine that would prohibit this? >Inquiring mind wants to know... This was the first thing I complained about when I knew I was getting an LC for my office. The problem I believe is the fact that the VRAM SIMM socket doesn't know how to access more than 512k. I think that it would be amazing if Apple could reconfigure the VRAM socket to handle 1M and 4M SIMM chips thereby giving 16 bit and 32bit color on the 13" RGB. The only other meathod of getting more than 8 bit color on a 72 dpi monitor is to use up the PDS slot for a video card, of which I don't believe any exist as of right now. I'll have to re-check my MacWeeks to be sure. Later. -- -Hades Hustler Emeritus, Alpha Theta Co-ed Fraternity hades@Eleazar.Dartmouth.Edu -You know the economy's going to hell when drug dealers buy fuel efficient cars
lemke@radius.com (Steve Lemke) (05/01/91)
gerhard@cs.arizona.edu (Gerhard Mehldau) writes: }Now, does anyone know what is preventing Apple (or third }parties, for that matter) from making 1M or 2M VRAM chips, }that would allow me to run the 13" monitor in 16- or 32-bit }mode? Technology? Price? Also, would the LC be able to }take advantage of such chips, or are there some limitations }in the design of the machine that would prohibit this? It takes more than extra RAM - it takes logic to route the proper bits from the RAM to the Digital to Analog Convertor (DAC). It also takes a DAC that can properly generate red, green, and blue signals given three different eight bit inputs (as opposed to a DAC that simply takes eight bits in and uses an on-chip color lookup table to map the 8-bit values to the proper R, G, and B values). This is why 24-bit video boards cost so much more than 8-bit video boards... -- ----- Steve Lemke, KC6QDT - Software Engineering, Radius Inc., San Jose ----- ----- Reply to: lemke@radius.com -- U.C. Santa Barbara ECE Class of '89 ----- ----- "I'm not a UNIX wizard, but I play the Postmaster at radius.com." -----
gerhard@cs.arizona.edu (Gerhard Mehldau) (05/02/91)
In a previous post, I asked: } Now, does anyone know what is preventing Apple (or third } parties, for that matter) from making 1M or 2M VRAM chips, } that would allow me to run the 13" monitor in 16- or 32-bit } mode? Technology? Price? Also, would the LC be able to } take advantage of such chips, or are there some limitations } in the design of the machine that would prohibit this? In article <1448@radius.com>, lemke@radius.com (Steve Lemke) writes: > It takes more than extra RAM - it takes logic to route the proper bits from > the RAM to the Digital to Analog Convertor (DAC). It also takes a DAC that > can properly generate red, green, and blue signals given three different > eight bit inputs (as opposed to a DAC that simply takes eight bits in and > uses an on-chip color lookup table to map the 8-bit values to the proper > R, G, and B values). But doesn't the LC need to have such a DAC already, if it can display 16-bit color for the small screen? With the appropriate amount of VRAM, it should be able to handle at least 16-bit color for larger screens at well. No? - Gerhard -- -> Gerhard Mehldau Dept. of Computer Science internet: gerhard@cs.arizona.edu University of Arizona uucp: {cmcl2,noao,uunet}!arizona!gerhard Tucson, AZ 85721, U.S.A. voice: +1 (602) 621-4632
klingspo@mozart.cs.colostate.edu (Steve Klingsporn) (05/02/91)
It is possible to do 32-bit color video on the LC. Whether or not it's possible to expand the VRAM, I do not know, but you'll bet that some vendor (SuperMac? Radius?) will come out with a card. Has to be. Steve Klingsporn