10 REM Program Spline1
   20 REM Version B1.0
   30 REM Author  David James
   40 REM BEEBUG  June 1990
   50 REM Program Subject to copyright
   60 :
  100 adr=&70:len=&76:dots=&77
  110 S%=&2C00:C%=&2F00
  120 FOR I%=0 TO 2 STEP 2
  130 P%=C%:[
  140 OPT I%
  150 .setadr LDA adr:STA asl+1
  160 LDA adr+1:STA asl+2:RTS
  170 :
  180 .asl ASL &FFFF,X:RTS
  190 :
  200 .block16 LDA #0:LDX #0
  210 .L1 JSR asl:ROL A
  220 CPX #&06:BNE L2
  230 PHA:LDA #&78:CLC
  240 ADC asl+1:STA asl+1
  250 LDA #&02:ADC asl+2:STA asl+2
  260 PLA
  270 .L2 INX:INX
  280 CPX #&10:BNE L1
  290 .endblock16 LDY &78
  300 STA (&74),Y:INY
  310 STY &78:BNE rts
  320 INC &75:.rts RTS
  330 :
  340 .block48 LDA #0:TAX:TAY
  350 .L3 JSR asl:BCC L4
  360 CLC:ADC (&72),Y
  370 .L4 INX:INY
  380 CPY dots:BNE L3
  390 JMP endblock16
  400 :
  410 .data
  420 EQUD &030C30C0
  430 EQUD &10204080
  440 EQUD &01020408
  450 :
  460 .blockdo LDA dots:CMP #&10
  470 BNE not16
  480 LDA #&07:.loop16 PHA
  490 JSR setadr:JSR block16
  500 PLA:SEC:SBC #1
  510 BPL loop16:RTS
  520 .not16
  530 LDA#data MOD256:STA &72
  540 LDA#data DIV256:STA &73
  550 LDA dots:CMP #8
  560 BNE not8
  570 LDA &72:CLC
  580 ADC #&04:STA &72
  590 .not8 LDA #7
  600 .loop48 PHA:JSR setadr
  610 JSR block48
  620 PLA:SEC:SBC #1:BPL loop48
  630 RTS
  640 :
  650 .main
  660 LDA #&00:STA &74:STA &78
  670 LDA #S% DIV 256:STA &75
  680 .mainloop JSR blockdo
  690 LDA #&08:CLC:ADC adr:STA adr
  700 LDA #&00:ADC adr+1:STA adr+1
  710 DEC len:BNE mainloop:RTS
  720 ]
  730 NEXT
  750 A%=0:X%=&FF
  760 *KEY0"LO.""BBCBAN2""|M*T.|MFOR L%=0 TO &1700 STEP 4:L%!&E00=L%!PAGE:NEXT:PAGE=&E00|MO.|MRUN|M"
  770 *FX 138 0 128