HELP: Alarm for Digital Clock using TTL

can you please give us your idea how to display
ALARM and CURRENT TIME, using or not using multiplexers..

using TTL (not MCU)..we are using 4 Seven Segment Displays for both hours and minutes

12:00

this should how it works: for exmple, your current time is 12:00AM and we want to set the alarm at 12:30AM, by using for example a switch we can change the display to its ALARM mode, and then after switching it again, the 7SegDisplay should display the current time and alarm time..

HERE are the all switches used:

1. ALARM on/off (SPDT)
2. ALARM mode (relay switch)
3. TIME mode (relay switch)
4. HOUR (tack switch)
5. MINUTE (tack switch)


we appreciate your help..

hi,
If you use the SEARCH on the upper menu bar, for digital clocks there are a number of threads.

yeah, i know..but the posts there does not answer my problem..i appreciate your help..