Digital Clock with an alarm

[Sangharsh Sharma]

Hello everyone.
I'm working on a digital clock circuit for my hobby project. I completed the circuit but I couldn't figure out how to add an alarm to the circuit. A little help would be appreciated. Thanks.
(I've made the digital clock circuit using 7490 ic, 7447 ic and logic circuits). The simulation pic is attached below:
 

[Zero999]

The easiest way would be to use a binary comparator, which would set its output high, once the numbers exceed the set value, which could be determined by BCD rotary switches.

Of course it would be even easier to use a microcontroller, but this is probably an educational project to learn about logic gates, so that would defeat the purpose.