Re: 6809 assembly knowledge needed

Date: Tue, 02 Feb 2010 19:21:00 +0100
Message-ID: <>
Hallo Per,

> How about plugging a 6809 into a 6510 socket..? :)

I have thought about that many years ago after my first 65816 broke down. 
To be able to run at 1 MHz, the 6809 needs a 4 Mhz clock. Creating it from 
the onbard ~1 MHz is possible but how to synchronize the Q and E output 
with Phi0?

IIRC it was one of the CBM-Hackers that pointed me out to the 6809E which 
you have to provide with Q and E. But it seems that these are rare. I have 
lot of 68x09's but only lately I found by acident a 6809E (and I have still 
to desolder it). IMHO it is doable but would it create enough interest?  

Three ways to implement the 6809(E):
1- replace the 6510 directly
2- as cartridge like the CP/M cartridge: just the 6809 and some logic to 
(de)activate it
3- as cartridge where the 6809 has its own RAM and ROM and exchanges data 
with the C64 by means of:
  - DMA, as the SCPU does
  - 6526/6821 I/O-bridge
Personal choice: 2.

Software shouldn't be a problem IMHO: FLEX.

Main problem: who has time and interest to develop it? (I have only a lot 
of the last :( )

   / __|__
  / /  |_/     Groetjes, Ruud Baltissen
  \ \__|_\

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Received on 2010-02-02 19:00:04

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