After 14 years, I thought it was time I gave the Micro UK101 a re-visit and a refresh.
I have updated the circuit slightly to make the chip selects based purely on address lines, and OE and WR more conventional, using Phi2 and the R/W. The E select on the 6850 is also now utilised, so follows "conventional" connections.
Also added the memory map to allow you to see the reasoning behind the decode logic.
I have also taken on board all comments in this forum, and updated the MAX232 and clock generator circuits with what you have said - I DO listen
The layouts and circuit has been re-visited and quite a bit of work done to improve the images - they are also now in colour (I can use Visio better than I could 14 years ago!).
The URL of the page is unchanged...
Please refresh the page in your browser to make sure you see the latest version - it will show last update of 18th January 2012 near the top.