nanogui: Drawing modes
Subject:
RE: Drawing modes
From:
Greg Haerr ####@####.####
Date:
19 May 1999 23:37:15 -0000
Message-Id: <01BEA21D.FCA8BA20.greg@censoft.com>
> Now I'm really confused. Isn't that still read-modify-write? It's a
> read, followed by modifying the data, followed by a write. Maybe we
> need some better definitions. How do you define rmw?
You'e right. I meant by EGA/VGA rmw that you can use the following
type code (yours) to access video ram. Note, as you say, that the 0x42 doesn't
matter, as we're talking to latches.
volatile char *x;
...set up registers...
y = *x; *x = 0x42;
...finish up...
On "other" rmw, it just means that you read memory, modify it,
and write it back, and the memory retains the written back value, not concerned
with hw latches...
Greg
> --
> "...In the UNIX world, people tend to interpret `non-technical user'
> as meaning someone who's only ever written one device driver."
> --Daniel Pead
>
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