Henk Gooijen wrote:
I have build that circuit, but can't remember exactly how
the 8 switches connect combined to the single clock input ...
How about a MM54HCT149 8-line to 8-line priority encoder?
http://eshop.engineering.uiowa.edu/NI/pdfs/00/53/DS005364.pdf
Mike Loewen mloewen at cpumagic.scol.pa.us
Old Technology
http://sturgeon.css.psu.edu/~mloewen/Oldtech/