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* 6522 x 2ea
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* Registers
n = slot#
6522-#1.offset = $Cn00
6522-#2.offset = $Cn80
$00 : ORB
$01 : ORA
$02 : DDRB, 1=output bit / 0=input bit
$03 : DDRA, 1=output bit / 0=input bit
$04 : T1CL, Timer1 Counter LowByte
$05 : T1CH, TImer1 Counter HighByte
$06 : T1LL, Timer1 Latch LowByte (not implemented)
$07 : T1LH, Timer1 Latch HighByte (not implemented)
$08 : T2CL, TImer2 Counter LowByte (not implemented)
$09 : T2CH, TImer2 Counter HighByte (not implemented)
$0A : SR, Shift Register (not implemented)
$0B : ACR, Auxllary Control Register
[7:6] Timer1 Control
00 : OneShot (not implemented)
01 : Continuous
[5:0] not implemented ( = %000000 )
$0C : PCR, Peripheral Control Register (not implemented)
$0D : IFR, Interrupt Flag Register
[7] IRQ: 0=clear interrupt / 1=enable interrupt
[6] Time out of Timer1: 0=cleared by read or write T1C.LH / 1= set by time out
$0E : IER, Interrupt Enable Register
$0F : IOA, ORA/IRA no handshake (not implemented)
* Interrupt routine
IFR[6] = 1
IER[6] = 1
OnClock
-> dec. timer1
-> if timer1<=0,
=> set IFR[7] = 1
=> reload timer1
-> if IFR[7]==1
=> send IRQ
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* AY-3-8910
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REGISTER
ADDRESS SOUND PARAMETERS
0 Tone Period Fine Tune for channel A
1 Tone Period Coarse Tune for channel A
2 Tone Period Fine Tune for channel B
3 Tone Period Coarse Tune for channel B
4 Tone Period Fine Tune for channel C
5 Tone Period Coarse Tune for channel C
6 Noise Period (not implemented)
7 Enable
8 Amplitude for channel A
9 Amplitude for channel B
10 Amplitude for channel C
11 Envelope Period Fine Tune (not implemented)
12 Envelope Period Coarse Tune (not implemented)
13 Envelope Shape (not implemented)
14 Unused
15 Unused
- 노이즈, 엔벨로프 기능 아직 미구현
잡음이 있지만, 디버깅용이니까 자기만족.
