How Do Keyboard Scan Codes Work with Modified Keys like 'Alt' or 'Ctrl'?

[aychamo]

Hey guys;

I was driving the other night, and I was thinking about some programs I used to write many years ago in Pascal (like ~ 11-12 years ago in TurboPascal 7.0, or was it 6.0?) in which I used to catch the keyboard scan codes.

I realized that I neve caught a keyboard scan code for a key that was modified with "Alt" or "Ctrl". I remember for an arrow key you would check for (0 + 75) or something. How would you check the keyboard "buffer" for presence of a key which is modified with Alt or Ctrl?

Also, would, say, "Alt-F4" be a single keyboard scan code, or would the keyboard interpret it as mulitple keypresses?

I'm just curious :)

 

[TenaliRaman]

http://www.jpsoft.com/help/index.htm?keyscanexpl.htm

If u have any doubts here post back and i will try to clarify.