Sf/sram

[SteveFosdick]

Dave, noting what you said I won't be offended if you cherry pick but this is as easy a way as any to share a pointer to the branch I have checked this into. Issue #5

[hoglet67]

Steve, I'll probably get onto this next week. I'm a little tied up and the moment with Dave and Daniel debugging some strange clocking issues with the new Electron AP5.