Date   : Tue, 08 Oct 2002 08:46:40 +0100
From   : "Colin f" <colin@...>
Subject: Re: speed

----- Original Message -----
From: "Richard Gellman" <splodge@...>
To: "BBC Micro Mailing List" <bbc-micro@...>
Sent: Monday, October 07, 2002 7:57 PM
Subject: RE: [BBC-Micro] speed


> >Is it possible to speed a BBC micro up. Perhaps by disabling certain
events
> or by any other method?.
>
> If you have the skills and the patience...
>
> You can desolder the 6502, and put in a 65C102. You will need pinouts for
> this, as I *think* they have different pin configurations.
> Then you need to rewire the entire clock system for a 6Mhz CPU clock. The
> BBC Micro uses a system of 2Mhz dropped to 1Mhz for accessing certain
> devices.

<snip>

You might find it a lot easier to overclock a 6502 second processor unit.
This would save having to work round the problems with video, 1MHz bus
access etc.
A 65C816 can run as a pin compatible 6502, but at 20MHz.
This CPU was used in the Commodore 64 Super CPU - see
http://come.to/supercpu
You'll also find a 65816 inside the Acorn Communicator.

Colin f