[Coco] What about the double speed upgrade?

[Leon Howell]

I don't know if I'll *ever* get a fast drive working, but there are several 
ways of making the CPU even faster, and one of them is the double speed (3.568 
mhz) upgrade on sockmaster's web site.

Are Mark's 6309's capable of 3.5-4.0 mhz? if not, where can I get one that is?

What about compatability? Are there programs that will have problems at this 
speed? What about hardware compatability?