The 2:1 selector outputs one of two 8 bit inputs. Also known as a multiplexer.
Interface and Operation¶
This is the interface of a 2:1 selector:
This is how it operates:
|out||8||Output, either A or B.|
|A/B||1||When low, A is output, when high, B is output|
- Two 74HCT157s are used to choose between the two inputs.
- LEDs with current limiting resistors are used to display the output.
Due to 2:1 selectors being required in different parts of the computer, the layout on the breadboard of A, B and out sometimes need to differ.
This is the A B out layout:
This is the out A B layout:
Different coloured wires are used in the Fritzing images above to help track the A, B and out bits. When creating the computer only green wire was available :(.