On Fri, Aug 2, 2019 at 11:15 AM Liam Proven via cctalk < cctalk@classiccmp.org> wrote:
> 1993 article on building a multiprocessor 6809 box. > http://www.bradrodriguez.com/papers/6809cpu.htm > I disagree very much with the author's advice to use the MC6809 rather than the MC6809E. With the E version you have to supply a quadrature clock, but all that's required to generate that is a single-phase 4x clock (which you need with either the E or non-E part) and a single 74HCT74. If you feed your single-phase 4x clock into multiple 6809 (non-E) parts, their E clock phases won't match, but will be off by arbitrary multiples of 1/4 cycle, which makes the shared memory design unnecessarily difficult.
