Re: System ROM 901227-01 wanted

From: Darren Spiteri (
Date: 2005-10-31 02:52:04

The problem was with the character ROM which would present false
character data when it was inadvertantly triggered by bus access.

The system accessing the bus would cause voltage spikes which the ROM
interpeted incorrectly, serving partial character data to VIC.

On 31/10/05, 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."

       Message was sent through the cbm-hackers mailing list

Archive generated by hypermail pre-2.1.8.