On Saturday, June 8, 2013 7:40:20 AM UTC+10, DaveC wrote:
Have a part on a display / control board from industrial equipment, marked
with:

UCN 4815A

It's listed in my 1984 Sprague data book as a BiMOS Latch/Source Driver.

I believe it has been superseded by the UCN-5815A which appears to be directly compatible.

http://pdf1.alldatasheet.com/datashe.../datasheet.pdf