Port
Writing
| Description
|
Zone
|
Address
|
| Part I address (A0)
|
Z80
|
$4000
|
| M68K
|
$A04000
|
| Part I address (D0)
|
Z80
|
$4001
|
| M68K
|
$A04001
|
| Part I address (A1)
|
Z80
|
$4002
|
| M68K
|
$A04002
|
| Part I address (D1)
|
Z80
|
$4003
|
| M68K
|
$A04003
|
Reading
Reading from any of the port will return the status register.
| Bit |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Def |
1 : Busy
0 : Ready for new data
|
Unused
| 1 : Timer A Overflow
0 : Not overflow
| 1 : Timer B Overflow
0 : Not overflow
|
Registers
0x22 - LFO
| Bit |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Def |
Unused
|
LFO Enable
| LFO Frequency
|
| Value
|
LFO Frequency
|
| 0
|
3.98
|
| 1
|
5.56
|
| 2
|
6.02
|
| 3
|
6.37
|
| 4
|
6.88
|
| 5
|
9.63
|
| 6
|
48.1
|
| 7
|
72.2
|
0x24/0x25 - Timer A
| Bit |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Def |
Timer A (bit 10-2)
|
| Bit |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Def |
Unused
|
Timer A (bit 1-0)
|
0x26 - Timer B
| Bit |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Def |
Timer B
|
0x27 - Channel 3/6 and Timer control
| Bit |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Def |
Channel 3 Mode
0 : Normal
1 : Special
2/3 : Illegal
|
1 : Timer B Reset
0 : No effect
| 1 : Timer A Reset
0 : No effect
| 1 : Timer B overflow set the read register flag
0 : Timer B overflow don't set the read register flag
| 1 : Timer A overflow set the read register flag
0 : Timer A overflow don't set the read register flag
| 1 : Start Timer B
0 : Stop Timer B
| 1 : Start Timer A
0 : Stop Timer A
|
0x28 - Channel Operator control
| Bit |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Def |
Operator
|
Unused
| Channel
|
0x2A/0x2B - DAC
0x2A
| Bit |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Def |
DAC Data
|
0x2B
| Bit |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Def |
1 : DAC Enable
0 : DAC Disable
|
Unused
|
0x30-0x90 - Single operator
0x30
| Bit |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Def |
Unused
|
DT1
| MUL
|
| Bit |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Def |
Unused
|
Total level (envelope's highest amplitude)
|
| Bit |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Def |
RS (Rate scaling)
|
Unused
| AR (Attack rate)
|
| Bit |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Def |
AM (Amplitude modulation enable)
|
Unused
| D1R (first decay rate)
|
| Bit |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Def |
Unused
|
D2R
|
| Bit |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Def |
Unused
|
SSG-EG
|