PIC PS/2 Keyboard Circuit and Code - 5 Keys Only

This is similar to what's been discussed in this thread: https://electro-tech-online.com/viewtopic.php?t=1136

I want to use a PIC. I already have a PIC16F84A. I only have 5 inputs (5 Keys or Buttons) and 4 outputs (a PS/2 keyboard usually has 6 leads, but only 4 are used, which I can see by looking at the end of the PS/2 plug of my keyboard cord).

Once 1 of the buttons are pressed, the PIC will send out a "signal" to the Keyboard port on the motherboard side. As I've been reading, I guess there are keyboard scan codes that are being sent out.

However, there is one exception, which might be the hardest part. One of the keys I need must send out a string. This string says: qv r:/*.avi . So in actuality, I'm using 4 keyboard keys (which will become buttons), and 1 button that will send out a line.

In summary, when 1 button is pressed, it will tell the PIC to send out a specific "scan code" or a string.

Inputs:

4 Keys:
1- Esc
2- Space Bar
3- Left arrow
4- Right arrow

1 Button:
1- sends out a string


any advice? thanks.

The ps/2 protocol, including some pic code, is explained here
**broken link removed**

I've looked at that website, and it's very useful. However, there's a lot of "other" stuff, and it's difficult to say what I need and what I don't need for my *specific* application. Can anyone give me some more advice? Thanks.