Date   : Tue, 07 Apr 2009 22:04:04 +0200
From   : kortink@... (John Kortink)
Subject: Faster, faster

On Sat, 04 Apr 2009 17:40:00 +0200, I wrote:

>[...]

Okay, a more revealing snapshot (watch out, rather big,
4.7 MB) :

http://212.123.133.121:8080/home/media/images/ReCo6502_Proto.jpg

It is a 'remake' of the 6502 second processor for the
BBC range. With a few extras that were irresistible :

- Supports existing 65C02, 3 or 4 MHz
- Supports WDC 65C02 or 65C816, 14 MHz (and can run
  at this speed, i.e. with the ULA accessed at 3 MHz)
- Supports up to 512 KB of RAM, which can (currently)
  be bankswitched, or used 'as is' by a 65C816 running
  in native mode (16-bit data, 24-bit addressing).

The 65C816's native mode is (as yet) not supported by
the Tube OS and e.g. BASIC. But it is possible to run
machine code programs that temporarily switch to native
mode and can then use 512 KB linearly addressable memory.

The 'remake' does need the box and the original Tube ULA
from an existing 6502 second processor. I.e. (as yet ...)
it is not standalone, but either a replacement or an
upgrade. This is, and will probably remain, its main
purpose.


John Kortink

-- 

Email    : kortink@...         
Homepage : http://www.inter.nl.net/users/J.Kortink

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