Well, I've had a bit of experience with the good ole' TI-83+. Here's a program I wrote a last year (if you're willing to go through the trouble of putting it on your calculator):
:
:AxesOff:ClrDraw:ZStandard:ZInteger
:ClrHome:Output(4,6,"REFLEX"):Output(5,3,"E-GAMES 2005"):Pause :ClrHome
:Menu("OPTIONS:","PLAY",0,"INSTRUCTIONS",A)
:Lbl A
Output(1,1,"HIT THE NUMBER 1 THROUGH 9 THATCORRESPONDS WITHTHE POSITION OF THE X ON THE SCREEN."):Pause :ClrHome
:Lbl 0
:Line(-16,-31,-16,31):Line(16,-31,16,31):Line(-47,11,47,11):Line(-47,-11,47,-11)
:0->S:120->T:0->C:0->N
:Lbl 1
:Text(1,1,"T")
:If 0=C
:Then
:31randInt(-1,1)->X
:20randInt(-1,1)->Y
:3(Y/-20+1)+3(X/31+2)->L
:Line(X-8,Y-8,X+8,Y+8):Line(X-8,Y+8,X+8,Y-8)
:End
:getKey->A
:If A=/0:1+N->N
:A-71->A
:If A>3:A-7->A
:If A>6:A-7->A
:If A=L:Then:Line(X-8,Y-8,X+8,Y+8,0):Line(X-8,Y+8,X+8,Y-8,0):S+1->S:0->C:End
:T-1->T
:If T>0:Goto 1
:ClrDraw
:ClrHome
:Output(4,7,"TIME"):Pause :ClrHome
:Output(1,1,"SHOTS:"):Output(1,8,N):Output(2,1,"HITS"):Output(2,7,S)
:Output(3,1,"Accuracy:"):Output(3,11,int(S100/N))
:Output(4,1,"SCORE:"):Output(4,8,int(S[sup]2[/sup]100/N))
:Pause
:If S100/N=100:Then:Output(5,1,"ACCURACY BONUS!"):Output(6,1,"TOTAL:"):Output(6,8,int(S[sup]2[/sup]100/N+300):Pause :ClrHome