Making new ROMs for the Vic-20 (again)

n my last post I talked about the W65C02 and how it brought me closer to having all-new parts in my Vicky Twenty, and at the same time giving it some new instructions.

That leaves the ROMs and the VIC. There's currently no replacement (as far as I'm aware) for the Vic1, but I have a new-old-stock one, so I think that's the best I can do for now.

I'd already fitted a home-made Kernal ROM replacement. These are harder to obtain than the other two ROMs. That particular one seems to be less reliable. They're usually socketed, indicating that Commodore knew this. If you have a black-screen Vic, it's a prime suspect.

That one wasn't very satisfactory. I didn't like the green adaptor board and thought it could be a bit more compact.

The other two ROMs were NOS (seem genuine) but all the same, I've always felt that they ought to be inside an original Vic-20, not a modern recreation.

So I've had my own PCBs made and have made 3 matching ROMs for Vicky. They're in keeping with the new processor on its own similar board. I've been working on the 'domed' soldering technique and with beautiful printed labels, they really look a treat and all's working well.

So we're very close to the goal of new parts, or at least not original parts. The case, keyboard and VIC are the only original parts now. Oops, nearly forgot the cartridge guide. Sven Petersen has our backs on that one I think.

Comments

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