10 REM TIN PAN ALLEY
   20 REM Mike Bostock
   30 REM (c) CET 1983 Published by BBC Publications
   40 REM version 2.0
   50 :
   60 ?&FE62 = 15 : REM 00001111 0-3 output 4-7 input
   70 port = &FE60 : REM user port location
   80 PROCmotors_on
   90 :
  100 ON ERROR IF ERR=17 PROCcomplete :PROCend: END ELSE REPORT:PRINT" at line ";ERL:PROCend:END
  110 :
  120 MODE7 : PROCoff
  130 PROCsetup
  140 PROCdouble (CHR$ 130 +program_name$,-1,4)
  150 IF NOT FNbuggy_connected THEN PROCnogo : PROCend : END
  160 :
  170 PROCcharacters
  180 PRINT TAB(2,20) "Do you need instructions ?  (Y/N) ";
  190 answer$ = FNinput (1,"YyNn")
  200 IF answer$="Y" OR answer$="y" THEN PROCinstructions
  210 :
  220 ON ERROR IF ERR=17 MODE7:PROCescape ELSE REPORT:PRINT" at line ";ERL:PROCend:END
  230 REM continues here after PROCerror
  240 IF end THEN CLS : PROCcomplete :PROCend: END
  250 :
  260 MODE4 : PROCoff :VDU19,1,4,0,0,0:VDU19,0,7,0,0,0:REM blue on white
  270 REPEAT
  280 REPEAT
  290 REPEAT
  300 IF answer$ = "1" OR answer$ = "3" THEN PROCclean1: ELSE CLS : PROCscreen2
  310 PROCcard
  320 PRINT TAB(9,30) "Press ESCAPE to halt."
  330 :
  340 PROCchoice1:answer$=FNinput (1,"1234")
  350 IF answer$="2" AND card>1 THEN PROCreplay:PROCspace1 (28) : CLS
  360 IF answer$="3" THEN PROCmanual
  370 IF answer$="4" THEN PROCtunes
  380 UNTIL answer$ = "1" AND card<100
  390 :
  400 PROCscan
  410 IF fault THEN PROCfault
  420 PROCerase
  430 IF fault = 0 THEN PROCspace1 (27)
  440 UNTIL card=100
  450 fault=3 : PROCfault
  460 UNTIL FALSE
  470 END
  480 :
  490 :
  500 :
  510 DEF PROCbar_check (direction,colour)
  520 LOCAL pulse,edge
  530 pulse = (direction OR 2)
  540 pulsecount = 0 : edge = 0
  550 REPEAT
  560 ?port = direction : PROCdelay(speedcontrol)
  570 ?port = pulse : PROCdelay(2)
  580 IF FNsensor = colour THEN edge = 1
  590 pulsecount = pulsecount + 1
  600 IF pulsecount > maxwidth THEN fault = 1
  610 UNTIL edge OR fault
  620 ENDPROC
  630 :
  640 DEF FNbuggy_connected = NOT (?port AND 32)
  650 :
  660 DEF PROCcalculate
  670 PROCcard
  680 number = INT((14*scantime(1)/(scantime(1)+scantime(2)))+0.5)
  690 notetype = INT((7*((duration-adjustment)/(scantime(1)+scantime(2))))+1)
  700 IF notetype < 1 THEN notetype = 1
  710 ENDPROC
  720 :
  730 DEF PROCcard
  740 PRINT TAB(7,1) card
  750 ENDPROC
  760 :
  770 DEF PROCcharacters
  780 REM box
  790 VDU 23,239,255,129,129,129,129,129,129,255
  800 REM block
  810 VDU 23,240,255,255,255,255,255,255,255,255
  820 REM #
  830 VDU 23,241,0,0,10,31,10,31,10,255
  840 REM # /no ledger
  850 VDU 23,238,0,0,10,31,10,31,10,0
  860 REM crotchet in space
  870 VDU 23,242,0,28,62,126,124,120,0,255
  880 REM crotchet on line
  890 VDU 23,243,0,0,0,0,0,28,62,255
  900 VDU 23,244,124,120,0,0,0,0,0,255
  910 REM minim on line
  920 VDU 23,247,0,0,0,0,0,28,34,255
  930 VDU 23,248,68,56,0,0,0,0,0,255
  940 REM minim in space
  950 VDU 23,246,0,28,34,66,68,120,0,255
  960 REM dot
  970 VDU 23,245,0,0,0,0,48,48,0,255
  980 REM dot/no ledger
  990 VDU 23,237,0,0,0,0,48,48,0,0
 1000 REM blank
 1010 VDU 23,249,0,0,0,0,0,0,0,0
 1020 REM crotchet/no ledger
 1030 VDU 23,250,0,28,62,126,124,120,0,0
 1040 REM minim/no ledger
 1050 VDU 23,251,0,28,34,66,68,120,0,0
 1060 REM bottom half crotchet/no ledger
 1070 VDU 23,252,124,120,0,0,0,0,0,0
 1080 REM bottom half minim/no ledger
 1090 VDU 23,253,68,120,0,0,0,0,0,0
 1100 ENDPROC
 1110 :
 1120 DEF PROCchoice1
 1130 PRINT TAB(4,25) "1  scan"; TAB(4,26) "2  replay"
 1140 PRINT TAB(4,27) "3  manual drive"; TAB(4,28) "4  examples"
 1150 PRINT TAB(24,27) "Your choice: ";
 1160 ENDPROC
 1170 :
 1180 DEF PROCchoice2
 1190 PROCerase
 1200 PRINT TAB(4,25) "1  test run"
 1210 PRINT TAB(4,26) "2  tune 1"
 1220 PRINT TAB(4,27) "3  tune 2"
 1230 PRINT TAB(4,28) "4  menu"
 1240 PRINT TAB(24,27) "Your choice: ";
 1250 ENDPROC
 1260 :
 1270 DEF PROCclean1
 1280 LOCAL I%
 1290 FOR I% = 6 TO 12 : PRINT TAB(12,I%) SPC(15) : NEXT
 1300 PROCstaves
 1310 PROCrectangle (380,639,864,892)
 1320 PRINT TAB(13,22) SPC(13)
 1330 PROCline (380,830,860,830)
 1340 PROCerase
 1350 ENDPROC
 1360 :
 1370 DEF PROCclef (x,y,N)
 1380 REM Draws a musical treble clef, starting at the co-ordinates x & y, the size being given by the third parameter, N
 1390 MOVE x,y
 1400 PLOT 1,  -N,   N:PLOT 1,   0,   N
 1410 PLOT 1,   N,   N:PLOT 1, 2*N,   0
 1420 PLOT 1, 2*N,2*-N:PLOT 1,   0,2*-N
 1430 PLOT 1,2*-N,2*-N:PLOT 1,3*-N,   0
 1440 PLOT 1,3*-N, 3*N:PLOT 1,   0, 2*N
 1450 PLOT 1, 7*N,16*N:PLOT 1,   0,   N
 1460 PLOT 1,  -N, 2*N:PLOT 1,  -N,  -N
 1470 PLOT 1,  0,28*-N:PLOT 1,  -N,  -N
 1480 PLOT 1,  -N,   N:PLOT 1,   N,   N
 1490 ENDPROC
 1500 :
 1510 DEF PROCdelay (count)
 1520 LOCAL delay
 1530 FOR delay = 1 TO count: NEXT delay
 1540 ENDPROC
 1550 :
 1560 DEF PROCdraw_card1
 1570 LOCAL line,K%
 1580 line = 1
 1590 IF N>13 THEN N=N-12
 1600 REPEAT
 1610 PRINT TAB(12,5+line) CHR$240
 1620 K%=1
 1630 REPEAT
 1640 IF K%=N THEN PRINT TAB(12+K%,5+line) " " ELSE PRINT TAB(12+K%,5+line) CHR$ 240
 1650 K%=K%+1
 1660 UNTIL K%=14
 1670 PRINT TAB(26,5+line) CHR$240
 1680 line=line+1
 1690 UNTIL line>6
 1700 ENDPROC
 1710 :
 1720 DEF PROCerase
 1730 LOCAL I%
 1740 FOR I% =25 TO 28 : PRINT TAB(1,I%) SPC(38); : NEXT
 1750 ENDPROC
 1760 :
 1770 DEF PROCescape
 1780 PROCmotors_on
 1790 PRINT TAB(0,1) CHR$(130) "BBC Buggy"
 1800 PROCdouble (CHR$ 130 +program_name$,-1,5)
 1810 PRINT TAB(7,10) "1. continue"
 1820 PRINT TAB(7,12) "2. delete last entry"
 1830 PRINT TAB(7,14) "3. start again"
 1840 PRINT TAB(7,16) "4. end program"
 1850 PRINT TAB(3,20) CHR$(134) "Your choice: ";
 1860 answer$ = FNinput (1,"1234")
 1870 IF answer$ = "2" AND card >1 THEN card = card - 1 : store = store - 1
 1880 IF answer$ = "3" THEN RUN
 1890 IF answer$ = "4" THEN end = 1
 1900 answer$ = ""
 1910 ENDPROC
 1920 :
 1930 DEF PROCfault
 1940 LOCAL count
 1950 count=0
 1960 IF fault = 1 THEN message$ = "READ FAULT"
 1970 IF fault = 2 THEN message$ = "This card cant be an octave card" : card = card -1
 1980 IF fault = 3 THEN message$ = "Two octave cards in a row":flag=0:card=card+1
 1990 IF fault = 4 THEN message$ = "No record of this card" : card = card - 1
 2000 PRINT TAB(1,30);SPC(38)
 2010 REPEAT
 2020 count = count + 1
 2030 PROCcentre (message$,30)
 2040 PROCdelay(600)
 2050 PRINT TAB(1,30);SPC(38)
 2060 SOUND 2,-15,197,1
 2070 PROCdelay(200)
 2080 UNTIL count=6
 2090 IF card<1 THEN card=1
 2100 ENDPROC
 2110 :
 2120 DEF PROCgreensleeves
 2130 LOCAL I
 2140 RESTORE 4950
 2150 FOR I = 1 TO 19 : READ N(I),T(I) : NEXT
 2160 store = 20
 2170 ENDPROC
 2180 :
 2190 DEF PROCinstructions
 2200 CLS : PROCdouble (CHR$ 130 +program_name$,-1,2)
 2210 PROCcentre ("In this program the Buggy will pick",5)
 2220 PROCcentre ("up musical information as it runs",7)
 2230 PROCcentre ("over a line of cards.",9)
 2240 PROCspace1 (23)
 2250 PROCcentre ("Select the first few cards which",12)
 2260 PROCcentre ("represent the first notes of a tune.",14)
 2270 PROCcentre ("The gap before the card represents",16)
 2280 PROCcentre ("the duration of the note on the card.",18)
 2290 PROCspace1 (23)
 2300 CLS
 2310 PROCdouble (CHR$ 130 +program_name$,-1,2)
 2320 PROCcentre ("After the buggy has scanned these,",5)
 2330 PROCcentre ("continue to lay the cards until",7)
 2340 PROCcentre ("the end of the tune is reached.",9)
 2350 PROCcentre ("(maximum " + STR$ size + " notes)",12)
 2360 PROCcentre ("Place an octave card after the note",15)
 2370 PROCcentre ("card if an octave is required.",17)
 2380 PROCspace1 (23)
 2390 ENDPROC
 2400 :
 2410 DEF PROClook_up1
 2420 RESTORE
 2430 LOCAL C%
 2440 C% = 1
 2450 flag = 0
 2460 REPEAT
 2470 READ note$,sharp,N,F,space,position
 2480 IF N = number THEN flag = 1
 2490 C% = C% + 1
 2500 UNTIL C% = 26 OR flag
 2510 IF flag = 0 THEN fault = 3
 2520 flag = 0
 2530 ENDPROC
 2540 :
 2550 DEF PROCmanual
 2560 REM Flush buffers
 2570 *FX 15,0
 2580 PROCerase
 2590 PROCcentre ("MANUAL DRIVE",26)
 2600 PROCcentre ("Use arrow keys to drive Buggy",27)
 2610 G$=FNwait
 2620 PROCcentre ("Press SPACE to continue",27)
 2630 REPEAT
 2640 G$=FNwait
 2650 *FX 4,1
 2660 IF INKEY (uparrow)   THEN PROCmove (forward,uparrow)
 2670 IF INKEY (downarrow) THEN PROCmove (backward,downarrow)
 2680 IF INKEY (leftarrow) THEN PROCmove (left,leftarrow)
 2690 IF INKEY (rightarrow)THEN PROCmove (right,rightarrow)
 2700 UNTIL GET$=" "
 2710 PROCerase
 2720 ENDPROC
 2730 :
 2740 DEF PROCmotors_off
 2750 ?port = 8
 2760 ENDPROC
 2770 :
 2780 DEF PROCmotors_on
 2790 ?port = 0
 2800 ENDPROC
 2810 :
 2820 DEF PROCmove (direction,key)
 2830 pulse = (direction OR 2)
 2840 REPEAT
 2850 ?port = direction : PROCdelay(4)
 2860 IF FNsensor = black THEN PRINT TAB(37,1) CHR$(240) ELSE PRINT TAB(37,1) CHR$(239)
 2870 ?port = pulse : PROCdelay(2)
 2880 UNTIL INKEY(key) = FALSE
 2890 ?port = 0
 2900 ENDPROC
 2910 :
 2920 DEF PROCnogo
 2930 PROCcentre ("Buggy not connected, END OF PROGRAM.",21)
 2940 PRINT
 2950 ENDPROC
 2960 :
 2970 DEF PROCnotetype
 2980 IF notetype<2 THEN N$="semiquaver"
 2990 IF notetype=2 THEN N$="  quaver  "
 3000 IF notetype=3 THEN N$="  quaver* "
 3010 IF notetype=4 THEN N$=" crotchet "
 3020 IF notetype>4 AND notetype<7 THEN N$=" crotchet*"
 3030 IF notetype>6 THEN N$="  minim   "
 3040 ENDPROC
 3050 :
 3060 DEF PROCoctave_check
 3070 factor = ((scantime(1)+scantime(2))/strip)
 3080 IF factor<5 AND factor>1.4 AND octave=0 THEN octave = 1 : card = card - 1 : number = number + 12
 3090 ENDPROC
 3100 :
 3110 DEF PROCprint
 3120 IF notetype>6 THEN A%=246:B%=247:C%=248:D%=249 ELSE A%=242:B%=243:C%=244
 3130 IF position>1 AND position<7 THEN D%=245 : E%=241 ELSE D%=237 : E%=238
 3140 IF notetype<>3 AND notetype<>5 AND notetype<>6 AND notetype<12 THEN D%=0
 3150 IF position=1 THEN A%=250:IF notetype>6 THEN A%=251
 3160 IF position<3 AND space=0 THEN C%=252:IF notetype>6 THEN C%=253
 3170 IF sharp=1 THEN PRINT TAB(X%,Y%-position) CHR$(E%) :X%=X%+1
 3180 IF space=1 THEN PRINT TAB(X%,Y%-position) CHR$(A%);CHR$(D%) ELSE PRINT TAB(X%,Y%-position) CHR$(B%);CHR$(D%);TAB(X%,((Y%+1)-position)) CHR$(C%)
 3190 IF notetype<16 THEN PROCstalk(X%,Y%,position)
 3200 ENDPROC
 3210 :
 3220 DEF PROCprocess1
 3230 IF octave = 1 THEN octaveflag = 1
 3240 octave = 0
 3250 PROCoctave_check
 3260 IF octave = 0 THEN PROCcalculate
 3270 IF card = 0 AND octave = 1 THEN fault = 2 : ENDPROC
 3280  IF octaveflag = 1 AND octave = 1 THEN fault = 3 : ENDPROC
 3290 IF octave = 0 THEN octaveflag = 0
 3300 PROClook_up1
 3310 N(card) = number : T(card) = notetype
 3320 PROCcard
 3330 ENDPROC
 3340 :
 3350 DEF PROCreplay
 3360 CLS
 3370 PROCcentre (program_name$,1)
 3380 PROCscore : card = 1
 3390 X%=5: Y%=11
 3400 PRINT TAB(8,30) "number=    note length=      ";TAB(2,1) "card"
 3410 REPEAT
 3420 number = N(card) : notetype = T(card)
 3430 PRINT TAB(16,30) number;" " TAB(32,30) notetype;" " TAB(7,1) card
 3440 PROClook_up1
 3450 type = notetype*5.5-2.5
 3460 SOUND 1,-volume,F,type
 3470 PROCprint
 3480 time = (60*type-(10*(number-1)))
 3490 PROCdelay(time)
 3500 X%=X%+notetype:IF X%>38 THEN X%=5 : Y%=Y%+8:IF Y%>34 THEN CLS:PROCscore:PRINT TAB(8,30);"number=     notetype=      ";TAB(2,1);"card":X%=5 :Y%=11
 3510 card = card + 1
 3520 UNTIL card = store
 3530 ENDPROC
 3540 :
 3550 DEF FNsensor = ADVAL(2) DIV 33000
 3560 :
 3570 DEF PROCsetup
 3580 *FX 4,1
 3590 size = 90
 3600 DIM N(size) , T(size)
 3610 DIM scantime(2)
 3620 program_name$ = "TIN PAN ALLEY"
 3630 REM keyboard INKEY values
 3640 uparrow    = -58 : forward    = 0
 3650 downarrow  = -42 : backward   = 5
 3660 leftarrow  = -26 : left       = 4
 3670 rightarrow = -122: right      = 1
 3680 space      = -99 : escape     =-113
 3690 nokey      = -129
 3700 REM other variables
 3710 pulselength= 100 : volume     = 15
 3720 speedcontrol= 15 : adjustment = 9.6
 3730 card       =  1  : octave     = 0
 3740 end        =  0  : fault      = 0
 3750 black      =  1  : white      = 0
 3760 octaveflag =  0  : maxwidth   = 100
 3770 bumpers    = 192
 3780 @%=02
 3790 answer$=""
 3800 ENDPROC
 3810 :
 3820 DEF PROCscan
 3830 fault = 0
 3840 PROCsensor1
 3850 IF fault =1 THEN ENDPROC
 3860 PROCprocess1
 3870 IF fault =2 OR fault =3 THEN ENDPROC
 3880 PROClook_up1
 3890 IF fault =4 THEN ENDPROC
 3900 PROCdraw_card1
 3910 X%=19:Y%=21
 3920 PROCprint
 3930 PROCnotetype
 3940 PRINT TAB(14,22) N$
 3950 SOUND 1,-volume,F,10
 3960 card = card + 1 : store = card
 3970 ENDPROC
 3980 :
 3990 DEF PROCscore
 4000 REM Draws three musical staves
 4010 LOCAL I,J,S
 4020 FOR I=834 TO 322 STEP -256
 4030 FOR J=0 TO 4
 4040 S = I-J*32
 4050 PROCline (20,S,1260,S)
 4060 NEXT J
 4070 PROCclef (80,S+32,8)
 4080 NEXT I
 4090 PROCrectangle (6,6,1274,1018)
 4100 ENDPROC
 4110 :
 4120 DEF PROCscreen2
 4130 PROCcentre (program_name$,1)
 4140 PRINT TAB(33,1) "bar ";CHR$ 239
 4150 PROCstaves
 4160 PRINT TAB(13,5) "CCDDEFFGGAABC"
 4170 PRINT TAB(14,4) CHR$238 " " CHR$238 "  " CHR$238 " " CHR$238 " " CHR$238
 4180 PROCrectangle (6,6,1274,1018)
 4190 PROCrectangle (380,639,864,892)
 4200 PROCline      (380,830,860,830)
 4210 PROCline      (6,930,1274,930)
 4220 PROCline      (6,80,1274,80)
 4230 PROCline      (6,240,1274,240)
 4240 PRINT TAB(2,1) "card "
 4250 ENDPROC
 4260 :
 4270 DEF PROCsensor1
 4280 bars = 0
 4290 REPEAT
 4300 fault = 0
 4310 bars = bars + 1
 4320 PRINT TAB(37,1) CHR$239
 4330 PROCbar_check (forward,1)
 4340 IF fault THEN UNTIL fault : ENDPROC
 4350 PRINT TAB(37,1) CHR$240
 4360 IF bars = 1 THEN duration = pulsecount ELSE strip = pulsecount
 4370 PROCbar_check (forward,0)
 4380 IF fault THEN UNTIL fault : ENDPROC
 4390 scantime(bars) = pulsecount
 4400 PRINT TAB(37,1) CHR$239
 4410 UNTIL bars=2 OR fault
 4420 ENDPROC
 4430 :
 4440 DEF PROCstalk(X,Y,P)
 4450 X = X*32+24
 4460 Y = 1068-(Y-P)*32
 4470 PROCline (X,Y-70+space*16,X,Y+space*16)
 4480 IF notetype<4 THEN DRAW X+16,Y-20+space*16
 4490 IF notetype=1 THEN MOVE X,Y-10+space*16:DRAW X+16,Y-30+space*16
 4500 VDU 4
 4510 ENDPROC
 4520 :
 4530 DEF PROCstaves
 4540 FOR K%=15 TO 19 : PRINT TAB(17,K%) "_____" : NEXT
 4550 PRINT TAB(17,20) "     ";TAB(17,21) "     ";TAB(17,13) "     ";TAB(17,14) "     "
 4560 ENDPROC
 4570 :
 4580 DEF PROCtest
 4590 LOCAL I%
 4600 FOR I =1 TO 24 :N(I)=I :T(I)=2 :NEXT
 4610 N(25) = 25 :T(25) = 4
 4620 store=26
 4630 ENDPROC
 4640 :
 4650 DEF PROCtunes
 4660 IF card<>1 THEN PROCcentre(" *Sample tunes will over-write yours*",30)
 4670 PROCchoice2 : answer$ = FNinput (1,"1234")
 4680 IF answer$="1" THEN PROCtest : PROCreplay : PROCspace1 (28)
 4690 IF answer$="2" THEN PROCweasel : PROCreplay : PROCspace1 (28)
 4700 IF answer$="3" THEN PROCgreensleeves : PROCreplay : PROCspace1 (28)
 4710 IF answer$ <> "4" THEN card = 1
 4720 CLS
 4730 answer$ = ""
 4740 ENDPROC
 4750 :
 4760 DEF PROCweasel
 4770 LOCAL I
 4780 RESTORE 4890 :FOR I = 1 TO 25 : READ N(I),T(I) : NEXT
 4790 store = 26
 4800 ENDPROC
 4810 :
 4820 REM note information
 4830  DATA C,0,1,53,0,1,C#,1,2,57,0,1,D,0,3,61,1,1,D#,1,4,65,1,1,E,0,5,69,0,2,F,0,6,73,1,2,F#,1,7,77,1,2,G,0,8,81,0,3,G#,1,9,85,0,3
 4840  DATA A,0,10,89,1,3,A#,1,11,93,1,3,B,0,12,97,0,4,C,0,13,101,1,4
 4850  DATA C#,1,14,105,1,4,D,0,15,109,0,5,D#,1,16,113,0,5,E,0,17,117,1,5,F,0,18,121,0,6,F#,1,19,125,0,6,G,0,20,129,1,6,G#,1,21,133,1,6
 4860 DATA A,0,22,137,0,7,A#,1,23,141,0,7,B,0,24,145,1,7,C,0,25,149,0,8
 4870 :
 4880 REM Pop Goes the Weasel
 4890 DATA 1,2,5,1,3,2,6,1,5,2,8,1,1,3
 4900 DATA 1,2,5,1,3,2,6,1,5,3,1,3
 4910 DATA 1,2,5,1,3,2,6,1,5,2,8,1,1,3
 4920 DATA 10,3,3,2,6,1,5,3,1,3
 4930 :
 4940 REM Greensleeves
 4950 DATA 12,2,15,4,17,2,19,3,21,1,19,2,17,4,14,2,10,3
 4960 DATA 12,1,14,2,15,4,12,2,12,3,11,1,12,2,14,4,11,2,7,5
 4970 :
 4980 :
 4990 REM Utilities
 5000 DEF PROCcomplete
 5010 CLS
 5020 PROCdouble (CHR$ 131 +"Mission completed.",-1,10)
 5030 ENDPROC
 5040 :
 5050 DEF PROCdouble (text$,X,Y)
 5060 IF X<0 THEN X = FNcentre (text$)
 5070 PRINT TAB(X-1,Y  ) CHR$ 141; text$
 5080 PRINT TAB(X-1,Y+1) CHR$ 141; text$
 5090 ENDPROC
 5100 :
 5110 DEF FNinput (length,allowed$)
 5120 LOCAL input$,ascii
 5130 PRINT STRING$(length,".");STRING$(length,CHR$ 8);
 5140 PROCon:*FX 15
 5150 REPEAT ascii = ASC FNwait
 5160 IF ascii=127 AND LEN(input$)>0 THEN input$ = LEFT$(input$,LEN(input$)-1):VDU ascii
 5170 IF INSTR(allowed$,CHR$ ascii) AND LEN(input$)<length THEN input$ = input$ +CHR$ ascii ELSE IF ascii<>13 AND ascii<>127 THEN ascii = 7
 5180 IF ascii = 13 AND LEN(input$)<1 THEN ascii = 7
 5190 IF ascii = 127 THEN VDU 46,8 ELSE VDU ascii
 5200 UNTIL ascii = 13 : PRINT : PROCoff
 5210 =input$
 5220 :
 5230 DEF PROCspace1 (line)
 5240 LOCAL I$
 5250 PROCcentre ("Press SPACE to continue",line)
 5260 *FX 15
 5270 REPEAT I$=FNwait : UNTIL INKEY(space)
 5280 REPEAT UNTIL INKEY(nokey)
 5290 ENDPROC
 5300 :
 5310 DEF PROCend
 5320 REM Switches motors off, resets cursor, EDIT & ESCAPE keys, buffers, and PRINT format
 5330 PROCmotors_off
 5340 PROCon
 5350 *FX 4
 5360 *FX 229
 5370 *FX 15
 5380 @% = 10
 5390 ENDPROC
 5400 :
 5410 DEF PROCoff VDU 23;11,0;0;0;0 : ENDPROC
 5420 DEF PROCon VDU 23;11,255;0;0;0 : ENDPROC
 5430 :
 5440 DEF PROCrectangle (X1,Y1,X2,Y2)
 5450 MOVE X1,Y1
 5460 DRAW X1,Y2
 5470 DRAW X2,Y2
 5480 DRAW X2,Y1
 5490 DRAW X1,Y1
 5500 ENDPROC
 5510 :
 5520 DEF PROCline (X1,Y1,X2,Y2)
 5530 MOVE X1,Y1
 5540 DRAW X2,Y2
 5550 ENDPROC
 5560 :
 5570 DEF FNcentre (text$) = 19-LEN(text$) DIV 2
 5580 :
 5590 DEF PROCcentre (text$,line)
 5600 PRINT TAB(1,line) SPC 38
 5610 PRINT TAB(FNcentre(text$),line) text$
 5620 ENDPROC
 5630 :
 5640 DEF FNwait
 5650 LOCAL I$
 5660 *FX 4,1
 5670 REPEAT
 5680 I$=INKEY$(10000)
 5690 IF I$="" THEN PROCmotors_off ELSE PROCmotors_on
 5700 UNTIL I$<>""
 5710 *FX 4
 5720 =I$
 5730 :