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# ksynth
# KSynth
Beginnings of a dual tone synthesizer for the Apple II
Everything is in this README, since it's small enough to copy and paste into an emulator for now.
##Two Tone Generator##
```
0300- A5 FD LDA $FD ; load second oscillator value into $FE
0302- 85 FE STA $FE ;
0304- A9 FF LDA #$FF ; load duration multiplier into $FC
0306- 85 FC STA $FC ;
0308- A4 FA LDY $FA ; load duration into Y
030A- A6 FB LDX $FB ; load oscillator into X
030C- CA DEX ; start countdown first oscillator, X
030D- EA NOP ; wait...
030E- EA NOP ;
030F- D0 05 BNE $0316 ; if X = 0, click. otherwise, skip
0311- 8D 30 C0 STA $C030 ; click
0314- A6 FB LDX $FB ; reset X to beginning of countdown
0316- C6 FE DEC $FE ; countdown second oscillator, $FE
0318- EA NOP ; wait...
0319- EA NOP ;
031A- D0 07 BNE $0323 ; if $FE = 0, click. otherwise, skip
031C- 8D 30 C0 STA $C030 ; click
031F- A5 FD LDA $FD ; reset $FE to beginning of countdown
0321- 85 FE STA $FE ;
0323- 88 DEY ; countdown duration
0324- D0 E6 BNE $030C ; if duration hasn't expired, return and count down oscillators
0326- A4 FA LDY $FA ; if duration has expired, reset duration
0328- C6 FC DEC $FC ; decrement duration multiplier
032A- D0 E0 BNE $030C ; if multiplier hasn't expired, return and count down oscillators
032C- 60 RTS ; all done
300: A5 FD 85 FE A9 FF 85 FC A4 FA A6 FB CA EA EA D0 05 8D 30 C0 A6 FB C6 FE EA EA D0 07 8D 30 C0 A5 FD 85 FE 88 D0 E6 A4 FA C6 FC D0 E0 60
```
##Player##
```
0330- A9 00 LDA #$00 ; start at zero
0332- AA TAX ; X = 0; LOOP
0333- BD 00 10 LDA $1000,X ; load note duration
0336- F0 31 BEQ $0369 ; if note is 0 duration, end the song
0338- 85 FA STA $FA ; store duration at $FA
033A- E8 INX ; increment to note value
033B- BD 00 10 LDA $1000,X ; load note value
033E- 85 FB STA $FB ; store note value at $FB
0340- 85 FD STA $FD ; store note value at $FD
0342- C9 FF CMP #$FF ; if note value is FF, rest
0344- D0 06 BNE $034C ; skip over if !=FF
0346- 8D 1E 03 STA $031E ; change the $C030 click to $$FF30
0349- 8D 13 03 STA $0313 ; change the $C030 click to $$FF30
034C- C6 FD DEC $FD ; decrement $FD for That Karateka Sound™
034E- 8A TXA ; put current note address in Accumulator
034F- 85 FF STA $FF ; store that in $FF
0351- 20 00 03 JSR $0300 ; play the actual note
0354- AD 13 03 LDA $0313 ; did we mess with the C030 click?
0357- C9 FF CMP #$FF ; if it's FF, we did. change it back.
0359- D0 08 BNE $0363 ; skip if !=FF
035B- A9 C0 LDA #$C0 ; set click points back to $c030
035D- 8D 1E 03 STA $031E ;
0360- 8D 13 03 STA $0313 ;
0363- E6 FF INC $FF ; increment to next note address
0365- A5 FF LDA $FF ; load Accumulator with next note address
0367- D0 C9 BNE $0332 ; branch to LOOP
0369- 60 RTS ;
330: A9 00 AA BD 00 10 F0 31 85 FA E8 BD 00 10 85 FB 85 FD C9 FF D0 06 8D 1E 03 8D 13 03 C6 FD 8A 85 FF 20 00 03 AD 13 03 C9 FF D0 08 A9 C0 8D 1E 03 8D 13 03 E6 FF A5 FF D0 C9 60
```
##Creating Music
Music is stored in the following format, beginning (by default) at $1000.
Starting address = A ($1000)
A+0 = duration
_e.g. FF = 1.63 seconds_
A+1 = note
_e.g. 59 = 440Hz A_
per chart at [https://www.seventhstring.com/resources/notefrequencies.html]
NOTE | C | C# | D | Eb | E | F | F# | G | G# | A | Bb | B |
|-----| ------ | ------ | ------ | ------ | ------ | ------ | ------ | ------ | ------ | ------ | ------ | ------ |
FREQ | | | | 155.6 | 164.8 | 174.6 | 185.0 | 196.0 | 207.7 | 220.0 | 233.1 | 246.9
BYTE | | | | FC | EF | E1 | D5 | C9 | BD | B3 | A9 | 9F
FREQ | 261.6 | 277.2 | 293.7 | 311.1 | 329.6 | 349.2 | 370.0 | 392.0 | 415.3 | 440.0 | 466.2 | 493.9
BYTE | 96 | 8E | 86 | 7E | 77 | 71 | 6A | 64 | 5E | 59 | 54 | 4F
FREQ | 523.3 | 554.4 | 587.3 | 622.3 | 659.3 | 698.5 | 740.0 | 784.0 | 830.6 | 880.0 | 932.3 | 987.8
BYTE | 4B | 47 | 43 | 3F | 3C | 38 | 35 | 32 | 2F | 2D | 2A | 27
##Bb scale:##
```
1000: 20 A9 20 96 20 86 20 7E 20 71 20 64 20 59 20 54 20 59 20 64 20 71 20 7E 20 86 20 96 FF A9 FF FF 10 A9 10 86 10 71 10 54 10 71 10 86 FF A9 00
```
##Karateka victory:##
```
1000: 10 a8 20 FF 8 c7 5 FF 10 a8 15 FF 25 7e 20 FF 10 63 08 FF 80 63 00 00
```