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From: gerhard@cs.arizona.edu (Gerhard Mehldau)
Newsgroups: comp.sys.mac.hardware
Subject: Re: 32-bit video for the LC?
Keywords: 32-bit video, LC, VRAM
Message-ID: <2649@optima.cs.arizona.edu>
Date: 1 May 91 18:42:08 GMT
References: <2599@optima.cs.arizona.edu> <1448@radius.com>
Organization: U of Arizona CS Dept, Tucson
Lines: 30

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