[plt-scheme] Please, help me out

I'm Salim , i'm nineteen years old, i'm studying right now computer 
engineering, my obssesion is to make games and live off it, drscheme was the 
language that i learned on the university , so i really need two answers to 
two problems i have right.
The first one is that how i can make a canvas that takes events from my 
controller pad, or as you know it "the game port", i've been looking all 
over internet and i found nothing, as you can see this isn't a homework, i'm 
really interested on programming games.
The second one is that when i switched drom drschem ver.103 to drscheme 
ver.203 my canvas that recieved keyboard events doesn't work anymore, it 
tells me that the override function is not a pair of identifiers, the code 
is as follows:

(define f (make-object frame% "frame" #f 300 300 20 20))
(define my-canvas%
  (class canvas% (frame)
    (override
      [on-char (lambda (event) (display (send event get-key-code)))])
    (sequence (super-init f))))
(define s (make-object my-canvas% f))
(send f show #t)

please, can you send it to me the way that works on ver.203, i've been 
looking in the new help desk how to work the override function and this new 
help is very ambiguous and i cannot understand it.
I appraise your time and attention.

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