Re: System ROM 901227-01 wanted

From: Marko Mäkelä (
Date: 2005-10-31 21:23:50

On Sun, Oct 30, 2005 at 07:53:37PM -0500, Glenn Holmer wrote:
> Is this what Brian Bagnall talks about in "On the Edge" (the new C= 
> history book)? see p. 263, where they're talking about the first 
> production run:
> "The C64 seemed to have a congenital defect with the video chip. "You 
> would see light blue sparkles on dark blue, especially after it heated 
> up", says Bil Herd... "They rewrote the code so that the unused 
> characters were changed to dark blue. It was sparkling dark blue on top 
> of dark blue so you couldn't see it."

Hmm, why does he say light blue on dark blue?  Shouldn't it be white on
dark blue?  The -01 KERNAL fills the screen with white spaces (regardless
of the selected cursor and background color).  Only the -03 KERNAL fills
it with cursor color (light blue) spaces.  The -02 KERNAL fills it with
background color (dark blue) spaces.

Anyway, this might be true.  When I tested my 6567R5 or 6569R1 about nine
years ago, I noticed that the sprites are sparkling.  It might have been
related to the horizontal sprite position or to the temperature of the chip.


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