** initial program **

# make room for the program below hi-res page 1
# note this allows the program to live slightly on the text page ($708), which is why you see a flash of garbage as the program starts
    0 LOMEM:1800

# this moves the program so it sits just below $2000
# the total program is 6190 bytes, so it will start at 2002 ($7D2)
    1 HIMEM:8192
# this sets the Integer BASIC program start pointer to $1BA5, which is the actual start
      : POKE 202,165: POKE 203,27
# set LOMEM to $1800, clear variables, start actual program
      :LOMEM:6144:CLR : GOTO 0

# everything from here on appears to be garbage (it's the assembly-language routines)
 8264 ,RUN LOMEM:**, IF , ^ ,RUN , ABS **, IF , ^ ,RUN ABS *-, IF ^ ;RUN ^ ,RUN *>=,=_ /*#2112HIMEM: IF 
[...more garbage...]


** actual main program **

    0 REM  *** APPLE-VISION ***       WRITTEN BY R.J. BISHOP
# scrolling text source
   20 DIM A$(51)
   30 A$="       BOB BISHOP PRESENTS ... APPLE-VISION!       "
# clear screen, print intro message
   40 CALL -936
   50 VTAB 10: TAB 10: PRINT "*** APPLE-VISION ***"
   55 VTAB 20: TAB 3: PRINT "COPYRIGHT 1978 APPLE COMPUTER, INC."
# delay, clear screen
   60 FOR K=1 TO 2500: NEXT K
   70 CALL -936
# clear hi-res screen, enable hi-res display
   80 CALL 2217: POKE -16297,0: POKE -16302,0: POKE -16304,0
# slowly draw lines, then add some text
   90 GOSUB 460: GOSUB 370
# pause
  100 FOR K=1 TO 1000: NEXT K

# scroll the message in A$ on the screen, pausing after each char
  110 FOR K=1 TO 45
  120 VTAB 13: TAB 12
# this is essentially MID$(A$,K,K+6)
  130 PRINT A$(K,K+6)
  140 FOR J=1 TO 75: NEXT J
  150 NEXT K
# pause
  160 FOR K=1 TO 1000: NEXT K
# do animated sequence
  170 CALL 2893
# short delay, then print we're done
  180 FOR K=1 TO 500: NEXT K
  190 VTAB 13: TAB 13: PRINT "THE"
  200 TAB 15: PRINT "END"
# delay, erase text, delay
  210 FOR K=1 TO 1500: NEXT K
  220 VTAB 13: TAB 13: PRINT "   "
  230 TAB 15: PRINT "   "
  240 FOR K=1 TO 4000: NEXT K
# randomize dancer
  250 GOSUB 540
# repeat, starting from the scrolling text
  260 GOTO 110
  270 END 

### draw a vertical, horizontal, or diagonal line from A,B to C,D
  280 DX=C-A:DY=D-B
  290 DELTA= ABS (DX): IF ABS (DY)> ABS (DX) THEN DELTA= ABS (DY)
  300 X=A:Y=B:INCX= SGN (DX):INCY= SGN (DY)
  310 FOR L=1 TO DELTA+1
# plot a point at X,Y
  320 POKE 16,X: POKE 17,Y
  330 POKE 18,0: CALL 2048
  340 POKE 18,1: CALL 2048
  350 X=X+INCX:Y=Y+INCY
  360 NEXT L: RETURN 

### draw background text
# configure character output to go to the HRCG at $B00 (2816)
  370 POKE 54,0: POKE 55,11
# wall sign
  380 VTAB 4
  390 TAB 25: PRINT "HOME"
  400 TAB 27: PRINT "SWEET"
  410 TAB 30: PRINT "HOME"
# TV controls
  420 VTAB 11: TAB 21: PRINT "OO"
  430 VTAB 15: TAB 21: PRINT "''"
  440 VTAB 16: TAB 21: PRINT ".."
  450 RETURN 

### draw all lines ###
# line definitions live from from $C00-CA3, as X0,Y0,X1,Y1
  460 FOR LOC=3072 TO 3236 STEP 4
  470 A= PEEK (LOC)
  480 B= PEEK (LOC+1)
  490 C= PEEK (LOC+2)
  500 D= PEEK (LOC+3)
# draw single line
  510 GOSUB 280
  520 NEXT LOC
  530 RETURN 

### randomize animation frames ###
# start at $D03 (but get the animation frame from $D00?)
  540 LOC=3331:ST= PEEK (LOC-3)
# if the animation frame is 1 (blank), we've reached the end
  550 IF PEEK (LOC)=1 THEN RETURN 
  560 TRY= RND (7)
# ST is the animation frame number (1-8)
# 2255 is $8CF, so this peeks a value at $8C8-8FF (all values there are 0 or 1)
# if the value is zero we retry
# the effect is to limit which frames can replace which other frames
  570 IF PEEK (7*ST-14+TRY+2255)=0 THEN 560
# convert random 0-6 to 2-8, store it
  580 ST=TRY+2: POKE LOC,ST
# on to the next one (3 bytes each)
  590 LOC=LOC+3: GOTO 550