Screensaver program

:Input A
:If A=1:Input Str1
:length(Str1)*6→V   #length in pixels of text
:AxesOff
:ClrDraw
:0→Xmin
:94→Xmax
:0→Ymin
:62→Ymax
:
:1→T
:62-8→B  #Minus amount of pixels from bottom
:92-V→R  #Minus amount of pixels from right side
:1→L
:
:Horizontal 1
:Vertical 1
:Horizontal 61
:Vertical 93
:
:randInt(2,B)→D   #Starting
:randInt(2,R)→O   #Coordinates
:
:Text(‾1,D,O,Str1) #Displays text for first time
:
:randInt(1,4)→H   #Starting Direction
:If H=1:92→M
:If H=2:74→M     
:If H=3:72→M
:If H=4:94→M
:
:While 1
:¦  # Those four lines add or subtract pixels 
:¦  # and make the movement work
:¦ D-(M=92)→D:O-(M=92)→O
:¦ D+(M=74)→D:O+(M=74)→O
:¦ D-(M=72)→D:O+(M=72)→O
:¦ D+(M=94)→D:O-(M=94)→O
:¦ 
:¦ If M=72:Then:  #if going up and left
:¦ ¦ If D=T:92→M  #if hit top bar, go down and left
:¦ ¦ If O=L:94→M  #if hit left bar, go up and right
:¦ End
:¦ If M=74:Then:  #if going up and right
:¦ ¦ If D=T:94→M  #if hit top bar, go down and right
:¦ ¦ If O=R:72→M  #if hit right bar, go up and to the left
:¦ End
:¦ If M=92:Then:  #if going down and left
:¦ ¦ If D=B:72→M  #if hit bottom bar, go up and right
:¦ ¦ If O=L:94→M  #if hit left bar, go down and right
:¦ End
:¦ If M=94:Then:   #if going down and right
:¦ ¦ If D=B:74→M   #if hit bottom bar, go up and right
:¦ ¦ If O=R:92→M   #if hit right bar, go down and left
:¦ End
:¦ 
:¦ Text(‾1,D,O,Str1)  #displays text
:¦
:¦ If 1:Then:     #debug info
:¦ ¦ Text(9,1,"D")
:¦ ¦ Text(9,5,D)
:¦ ¦ Text(15,1,"O")
:¦ ¦ Text(15,5,O)
:¦ End
:End

:Input "Change?: ",A
:If A=1:Input Str1
:Input "Big?: ",Q
:AxesOff
:ClrDraw
:0→Xmin
:94→Xmax
:0→Ymin
:62→Ymax
:
:2→L
:2→T
:If Q=1:Then:
:¦ length(Str1)*6→V
:¦ 61-8→B
:¦ 93-V→R
:End
:If Q≠1:Then:
:¦ length(Str1)*4→V
:¦ 61-7→B
:¦ 93-V→R
:End
:If V>91:Then:
:¦ Disp " ","      NO."
:¦ Stop
:End
:Horizontal(1
:Vertical 1
:Horizontal(61
:Vertical 93
:
:randInt(T,B)→D
:randInt(L,R)→O
:If Q=1:Text(‾1,D,O,Str1)
:If Q≠1:Text(D,O,Str1)
:randInt(1,4)→H
:If H=1:92→M
:If H=2:74→M
:If H=3:72→M
:If H=4:94→M
:
:While 1
:¦ 
:¦ D-(M=72)→D:O-(M=72)→O
:¦ D+(M=94)→D:O+(M=94)→O
:¦ D-(M=74)→D:O+(M=74)→O
:¦ D+(M=92)→D:O-(M=92)→O
:¦ 
:¦ If M=72:Then:
:¦ ¦ If D=T:92→M
:¦ ¦ If O=L:74→M
:¦ End
:¦ If M=74:Then:
:¦ ¦ If D=T:94→M
:¦ ¦ If O=R:72→M
:¦ End
:¦ If M=92:Then:
:¦ ¦ If D=B:72→M
:¦ ¦ If O=L:94→M
:¦ End
:¦ If M=94:Then:
:¦ ¦ If D=B:74→M
:¦ ¦ If O=R:92→M
:¦ End
:¦ If Q=1:Text(‾1,D,O,Str1)
:¦ If Q≠1:Text(D,O,Str1)
:¦ 
:¦ If O<L or O>R or D<T or D>B:Then:
:¦ ¦ randInt(T,B)→D
:¦ ¦ randInt(L,R)→O
:¦ ¦ Horizontal(1
:¦ ¦ Horizontal(61
:¦ ¦ Vertical 1
:¦ ¦ Vertical 93
:¦ End
:¦ 
:¦ 
:¦ If 0:Then:
:¦ ¦ Text(3,1,"M",M)
:¦ ¦ Text(9,1,"D")
:¦ ¦ Text(9,5,D)
:¦ ¦ Text(15,1,"O")
:¦ ¦ Text(15,5,O)
:¦ End
:End