Re: Dating a C-64 board

From: Ethan Dicks (
Date: 1999-04-18 17:20:37

--- Nicolas Welte <> wrote:
> Ethan Dicks wrote:
> >     ASSY 326298
> The ASSY number is the key to identify each board. The C64 service
> manual (also online on funet, I think) lists this number as 'original
> board'.
> The schematic of the original board suggests that there is a PAL/NTSC
> jumper, it should be a jumper wire like in the version A board that can
> be put either on location E2 or E3. The board layout shows an empty
> space near U29 in the video cage, maybe this is where the jumpers are.

Indeed there is.  I missed the legend because part of it is obscured by
a large cap, C33.
> Maybe they made a last minute change in the C64 for unknown reasons, and
> the video chip and the ROM were left configured for 1MHz.

The only crystal in this box is the 14.31818 MHz one that you would expect.

> And I think the VIC-20 runs at significantly higher clock speed,
> perhaps 1.2 MHz. I forgot ;-)

1.0Mhz, IIRC.

> It's a pity that you don't have your original C64 anymore. There's
> always the search for early chips to explore funny bugs. 

We didn't have to search for bugs... I got bit every time the machine
got warm.  I used to save every five minutes.

> I think Andreas Boose wanted to know once if the reset bit, that is
> disabled in all known VIC-II chips is perhaps active in very early
> versions. Perhaps you could try it on your machine?

Sure... give me some more details.  I can write a quick BASIC program if
I know what addresses you want wacked.  How does it behave in later C-64's?

Do You Yahoo!?
Get your free address at

This message was sent through the cbm-hackers mailing list.
To unsubscribe: echo unsubscribe | mail

Archive generated by hypermail 2.1.1.