Interfacing a PS/2 Keyboard for homebrew CPU

[bitbyteword3]

I'm designing an 8-bit CMOS CPU. I would like to interface a PS/2 keyboard as input for the computer. I would like to let it have 8-bit output (the scancode). What is a parity bit?

 

[Brevor]

https://en.wikipedia.org/wiki/Parity_bit

...........

 

[bitbyteword3]

.... LOL what?

 

[Brevor]

It's a link, everything you need to know about parity bit.

 

[Nigel Goodwin]

Is it just me?, or do others think it's strange that someone 'designing a CPU' doesn't know what a parity bit is.

It's like designing a car and not knowing what a wheel is.

 

[bitbyteword3]

*an application for the parity bit. Sorry, I don't know how I missed that. Any way to interface the keyboard?

 

[Nigel Goodwin]

*an application for the parity bit. Sorry, I don't know how I missed that. Any way to interface the keyboard?

Of course, it's a standard device - you need a bi-directional syncronous serial port, either in hardware or software.

https://en.wikipedia.org/wiki/PS/2_connector

 

[bitbyteword3]

I'm thinking of using the 4034 since I want a parallel output. Is this good? How will I get the scancode?

 

[ericgibbs]

I'm thinking of using the 4034 since I want a parallel output. Is this good? How will I get the scancode?

hi,
Do you have Visual Basic 5 or 6 on your PC.?
I have a simple ATKbd simulator source code, [ about 5 years old] written in VB, which you could use to work on the key codes.

You realise you need to send: key down code, key code, key up code for each key, also all the Caps/Alt keys etc.??

EDIT:
Note the HEX key codes on the key tops of this image.

 

[ericgibbs]

hi,
I have retraced the source of my original data, look thru these links.
https://www.google.co.uk/search?source=ig&hl=en&rlz=&q=microchip%2Fprojects%2Fkeyboard&btnG=Google+Search&aq=f&aqi=&aql=&oq=

This is the one I used.
https://electronic-engineering.ch/microchip/projects/keyboard/v1xx/keyboard_v1xx.html

 

[bitbyteword3]

I must be more specific - PS/2 Keyboard decoder with parallel output of all 11 bits. No MCUs.

 

[bitbyteword3]

I must be more specific - PS/2 Keyboard decoder with parallel output of all 11 bits. No MCUs. Any schematic for that?

 

[Nigel Goodwin]

You simply connect the PS2 keyboard directly to two I/O ports on your CPU, and do it in software.