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need help on a 3x4 key pad matrix

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rank44

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I have a project Z80 mini board one input and one output the input has a 74LS244 which go to the Z80.rom,ram can I connect the key pad matrix to the input will it work or do I need a microcontroller project or project
there is a schematic look at the input port I need to connect a key pad matrix
U3 is 74LS244

this input is from the Z80 mini board not the 74LS244
The input has 10 pin
pin1 5v+
pin2,3,4,5,6,7,8,9 go to the 74LS244
pin10 GND
I have check on the web site and found this IC mm74c922 has any one got a project that will help me connect the key pad matrix to the z80 mini board
 

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betwixt

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You have two options, either use a 74C922 to scan the keyoad for you and let it present the key number to the Z80 input port, or, you can connect the output port to the keypad columns and the input port to the keypad rows directly. If you use the second method, your Z80 software should make one, and only one, output pin to the keypad high at a time and read the input port to see if a key was pressed and they are linked together. Using the pin you made high and the pin you sensed with the connected signal you can determine which key was pressed.

Brian.
 

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