0000                             ;*****************************************************************************
0000                             ; 
0000                             ; erzeuge eine Tonleiter mit Rechecktönen
0000                             ; 
0000                             ; Zielfrequenzen
0000                             ; f =   261.63   293.66   329.63   349.23   392.00   440.00   493.88   523.25
0000                             ; 
0000                             ; Hardware: 6502, fcpu=1MHz, Junior Lerncomputer
0000                             ; 
0000                             ;*****************************************************************************
0000                             ; MOS6532 PIA Adressen
0000                PAD:      =   $1A80   
0000                PADD:     =   $1A81   
0000                PBD:      =   $1A82   
0000                PBDD:     =   $1A83   
0000                             ; Zero page für alle schnellen Variablen
0000                          .ORG   0   
0000   00           NOTE:     DB   0   
0001                             ; Programmstart
0300                          .ORG   $300   
0300   A9 01                  LDA   #$1   
0302   8D 83 1A               STA   PBDD   ; set PB0 to output
0305                MAINLOOP:      
0305   A9 C8                  LDA   #200   ; C
0307   85 00                  STA   note   
0309   20 40 03               JSR   playnote   
030C   A9 9E                  LDA   #158   ; D
030E   85 00                  STA   note   
0310   20 40 03               JSR   playnote   
0313   A9 79                  LDA   #121   ; E
0315   85 00                  STA   note   
0317   20 40 03               JSR   playnote   
031A   A9 68                  LDA   #104   ; F
031C   85 00                  STA   note   
031E   20 40 03               JSR   playnote   
0321   A9 49                  LDA   #73   ; G
0323   85 00                  STA   note   
0325   20 40 03               JSR   playnote   
0328   A9 2D                  LDA   #45   ; H
032A   85 00                  STA   note   
032C   20 40 03               JSR   playnote   
032F   A9 14                  LDA   #20   ; A
0331   85 00                  STA   note   
0333   20 40 03               JSR   playnote   
0336   A9 09                  LDA   #9   ; C
0338   85 00                  STA   note   
033A   20 40 03               JSR   playnote   
033D   4C 05 03               JMP   mainloop   
0340                PLAYNOTE:      
0340   A0 32                  LDY   #50   ; Tondauer
0342                LOOP:        
0342                             ; Standardverzögerung
0342   A2 B4                  LDX   #180   ; 5us×179+5us=900us
0344   20 58 03               JSR   shortdelay   ; 6 Takte
0347                             ; Zusatzverzögerung
0347   A6 00                  LDX   note   
0349   20 58 03               JSR   shortdelay   
034C   AD 82 1A               LDA   PBD   ; port B lesen
034F   49 01                  EOR   #$01   ; Bit 0 umschalten
0351   8D 82 1A               STA   PBD   ; zurückschreiben
0354   88                     DEY      
0355   D0 EB                  BNE   loop   
0357   60                     RTS      
0358                             ; Gesamtzeit = 5N+5 us
0358                SHORTDELAY:      
0358   CA                     DEX      ; 2 Takte
0359   D0 FD                  BNE   shortdelay   ; 3 Takte jmp , 2 no jmp
035B   60                     RTS      ; 6 Takte


PAD:                1A80 DEFINED AT LINE 13
PADD:               1A81 DEFINED AT LINE 14
PBD:                1A82 DEFINED AT LINE 15
                    > USED AT LINE 72
                    > USED AT LINE 74
PBDD:               1A83 DEFINED AT LINE 16
                    > USED AT LINE 25
NOTE:               0000 DEFINED AT LINE 20
                    > USED AT LINE 29
                    > USED AT LINE 33
                    > USED AT LINE 37
                    > USED AT LINE 41
                    > USED AT LINE 45
                    > USED AT LINE 49
                    > USED AT LINE 53
                    > USED AT LINE 57
                    > USED AT LINE 70
MAINLOOP:           0305 DEFINED AT LINE 27
                    > USED AT LINE 60
PLAYNOTE:           0340 DEFINED AT LINE 62
                    > USED AT LINE 30
                    > USED AT LINE 34
                    > USED AT LINE 38
                    > USED AT LINE 42
                    > USED AT LINE 46
                    > USED AT LINE 50
                    > USED AT LINE 54
                    > USED AT LINE 58
LOOP:               0342 DEFINED AT LINE 65
                    > USED AT LINE 76
SHORTDELAY:         0358 DEFINED AT LINE 80
                    > USED AT LINE 68
                    > USED AT LINE 71
                    > USED AT LINE 82