Here’s an entry in the Open 7400 Logic competition: Money counter
It’s a money counter based on pure 7400 logic and a bunch of 555. It can count 5 different types of coins. And it will show the current amount in the 7 segment displays.
There are 3 files, two IEE papers (one for spanish and one for english) and a ppt presentation (sorry for the lack of the english version of this one).
The documents are here