The computer’s clock is used to synchronize all operations. The clock we’re building is based on the popular 555 timer IC. The videos go into some detail on the operation of the 555 and use it in three different ways.
Our clock is adjustable-speed (from less than 1Hz to a few hundred Hz). The clock can also be put into a manual mode where you push a button to advance each clock cycle. This will be a really useful feature for debugging the computer later on.
- Astable 555 timer – 8-bit computer clock – part 1
- Monostable 555 timer – 8-bit computer clock – part 2
- Bistable 555 – 8-bit computer clock – part 3
- Clock logic – 8-bit computer clock – part 4
|3||555 timer IC|
|1||74LS04 (Hex inverter)|
|1||74LS08 (Quad AND gate)|
|1||74LS32 (Quad OR gate)|
|2||Double-throw toggle switch|
|2||Momentary 6mm tact switch|