Problem with programming

[Nobody/Anonymous]

Hi there.
I've been working with a friend on a project in Basic 256.
We're trying to create a pong game with two paddles, but somethings wrong the ball never comes back when ballx is over 275. It always says "You missed" but the ball never comes back.

Here's the code:

cls

print "Use the J and K keys to move the paddle"
print "Use the A and D keys to move the paddle"

fastgraphics

x1 = 285
y1 = 105
ballx = 30
bally = 0
ballxinc = 5
ballyinc = 5
xinc = 5

fastgraphics

x2 = 5
y2 = 105
xinc = 5

pause 0.0000000000000000000000000000000000001

loop1:
  a1 = key
  if a1 = 68 then y1 = y1 + 30
  if a1 = 65 then y1 = y1 - 30
  if y1 < 0 then y1 = 0
  if y1 > 200 then y1 = 200 
  gosub drawpaddle1
  gosub moveball
  gosub drawball

refresh

pause 0.0000000000000000000000000000000000001
  a2 = key
  if a2 = 75 then y2 = y2 + 30
  if a2 = 74 then y2 = y2 - 30
  if y2 < 0 then y2 = 0
  if y2 > 200 then y2 = 200
  gosub drawpaddle2
  gosub moveball
  gosub drawball
  goto loop1

refresh

moveball:
  ballx = ballx + ballxinc
  bally = bally + ballyinc
  if bally > 270 then ballyinc = -ballyinc
  if bally < 5 then ballyinc = -ballyinc
  if ballx > 295 then gosub checkball
  if ballx < 5 then gosub checkball
  return

pause 0.0000000000000000000000000000000000001

drawpaddle1:
  color gray
  rect 0,0,400,400
  color darkblue
  rect x1,y1,10,100
  color blue
  rect x1+1,y1+1,8,98
  rect x2+1,y2+1,8,98
  refresh
  return

checkball:
if bally < y1 - 70 then goto missed
if bally > (y1 + 150) then goto missed
ballyinc = -ballyinc
ballxinc = ((ballx -x1) - 50) / 10

pause 0.0000000000000000000000000000000000001

drawpaddle2:
  color gray
  rect 0,0,400,400
  color darkblue
  rect x2,y2,10,100
  color blue
  rect x2+1,y2+1,8,98
  rect x1+1,y1+1,8,98
color yellow
line 150,0,150,300

drawball:
color black
circle ballx, bally, 5
color white
circle ballx, bally, 4
return

missed:
print "You Missed!!"
bally = 10

refresh
return

Can you please help us?
It's very important!

Sincerly,
Alex and Philipp

[Nobody/Anonymous]

I am a beginner at programming but I'll try to help. This much I know: It's best to get a small portion of a program working and than add a little at a time while testing each small addition.
I just tried to make a pong game. Here are the steps I took.
1) Draw a rectangle in the middle of one end. (Easily done)
2) Find the key values for Q (up) and A (down). (Easily done)
3) Get the rectangle to move when pressing Q or A. (Easily done)
4) Draw another rectangle on the other end (Easily done)
5) Find key values for P (up) and L (up). (Easily done)
6) Get the second rectangle to move for P and L. (Easily done)
7) Get both rectangles to move at the same time while pressing Q or A and P or L. -Here's where I ran into trouble. If I pressed both Q and P (at the same time) the program would only recognize one as being pressed.
  I copied, pasted and ran your program and noticed the same thing -could only get one paddle to move at a time.  I wonder if it is a limitation of Basic 256 to only be able to work with one key being pressed at a time.  This maybe is the root cause of the problem you are having.
  It will take someone more knowledgeable than me to know how to get the program to recognize more than one key being pressed at a time (or if it is even possible).

Hope this helps, good luck, have fun,

Dave

[Nobody/Anonymous]

The checkball subroutine only checks for the paddle on the right (y1). Shouldn't there be a subroutine to check for the left (y2) paddle as well?

Dave