MB/Phasor: support AY(s) driving bus for 6522 PortA (ie. for the PSG READ function)

. Bump MB/Phasor save-state unit to v11
. Tested against mb-audit v1.50
This commit is contained in:
tomcw 2024-01-03 21:22:25 +00:00
parent cf0ae53018
commit 69151a2aff
4 changed files with 33 additions and 23 deletions

View File

@ -128,13 +128,6 @@ USHORT SY6522::SetTimerSyncEvent(BYTE reg, USHORT timerLatch)
//-----------------------------------------------------------------------------
void SY6522::UpdatePortAForHiZ(void)
{
BYTE ora = GetReg(SY6522::rORA);
ora |= GetReg(SY6522::rDDRA) ^ 0xff; // for any DDRA bits set as input (logical 0), then set them in ORA
SetRegORA(ora); // Empirically Phasor's 6522-AY8913 bus floats high (or pull-up?) if no AY chip-selected (so DDRA=0x00 will read 0xFF as input)
}
void SY6522::UpdateIFR(BYTE clr_ifr, BYTE set_ifr /*= 0*/)
{
m_regs.IFR &= ~clr_ifr;
@ -343,7 +336,7 @@ bool SY6522::IsTimer2Underflowed(BYTE reg)
//-----------------------------------------------------------------------------
BYTE SY6522::Read(BYTE nReg)
BYTE SY6522::Read(BYTE nReg, bool isDrivingBus/*=false*/)
{
BYTE nValue = 0x00;
@ -353,7 +346,7 @@ BYTE SY6522::Read(BYTE nReg)
nValue = m_regs.ORB | (m_regs.DDRB ^ 0xff); // Input bits read back as 1's (GH#1260)
break;
case 0x01: // IRA
nValue = m_regs.ORA; // NB. Inputs bits driven by AY8913
nValue = m_regs.ORA | (isDrivingBus ? 0x00 : (m_regs.DDRA ^ 0xff)); // NB. Inputs bits driven by AY8913 if in PSG READ mode
break;
case 0x02: // DDRB
nValue = m_regs.DDRB;

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@ -28,7 +28,6 @@ public:
void StopTimer2(void);
bool IsTimer2Active(void) { return m_timer2Active; }
void UpdatePortAForHiZ(void);
void UpdateIFR(BYTE clr_ifr, BYTE set_ifr = 0);
void UpdateTimer1(USHORT clocks);
@ -53,10 +52,10 @@ public:
USHORT GetRegT1C(void) { return m_regs.TIMER1_COUNTER.w; }
USHORT GetRegT2C(void) { return m_regs.TIMER2_COUNTER.w; }
void GetRegs(BYTE regs[SIZE_6522_REGS]) { memcpy(&regs[0], (BYTE*)&m_regs, SIZE_6522_REGS); } // For debugger
void SetRegORA(BYTE reg) { m_regs.ORA = reg; }
void SetRegIRA(BYTE reg) { m_regs.ORA = reg; }
bool IsTimer1IrqDelay(void) { return m_timer1IrqDelay ? true : false; }
BYTE Read(BYTE nReg);
BYTE Read(BYTE nReg, bool isDrivingBus = false);
void Write(BYTE nReg, BYTE nValue);
void SaveSnapshot(class YamlSaveHelper& yamlSaveHelper);

View File

@ -252,7 +252,7 @@ void MockingboardCard::WriteToORB(BYTE subunit, BYTE subunitForAY/*=0*/)
AY8913_Write(subunit, AY8913_DEVICE_B, value);
if (nAY_CS == 0)
m_MBSubUnit[subunit].sy6522.UpdatePortAForHiZ();
m_MBSubUnit[subunit].isDrivingBus = false;
}
else
{
@ -310,16 +310,19 @@ void MockingboardCard::AY8913_Write(BYTE subunit, BYTE ay, BYTE value)
break;
case AY_READ: // 5: READ FROM PSG (need to set DDRA to input)
pMB->isDrivingBus = true; // Initially default to true
if (QueryType() != CT_MegaAudio)
{
if (pMB->isChipSelected[ay] && pMB->isAYLatchedAddressValid[ay])
r6522.SetRegORA(AYReadReg(subunit, ay, pMB->nAYCurrentRegister[ay]) & (r6522.GetReg(SY6522::rDDRA) ^ 0xff));
r6522.SetRegIRA(AYReadReg(subunit, ay, pMB->nAYCurrentRegister[ay]) & (r6522.GetReg(SY6522::rDDRA) ^ 0xff));
else
r6522.UpdatePortAForHiZ();
pMB->isDrivingBus = false;
}
else
{
r6522.SetRegORA(0x00); // Reads not supported.
r6522.SetRegIRA(0x00); // Reads not supported. Bus not driven.
pMB->isDrivingBus = false;
}
if (m_phasorEnable && m_phasorMode == PH_Phasor) // GH#1192
@ -327,7 +330,7 @@ void MockingboardCard::AY8913_Write(BYTE subunit, BYTE ay, BYTE value)
if (ay == AY8913_DEVICE_A)
{
if (pMB->isChipSelected[AY8913_DEVICE_B] && pMB->isAYLatchedAddressValid[AY8913_DEVICE_B])
r6522.SetRegORA(r6522.GetReg(SY6522::rORA) | (AYReadReg(subunit, AY8913_DEVICE_B, pMB->nAYCurrentRegister[AY8913_DEVICE_B]) & (r6522.GetReg(SY6522::rDDRA) ^ 0xff)));
r6522.SetRegIRA(r6522.GetReg(SY6522::rORA) | (AYReadReg(subunit, AY8913_DEVICE_B, pMB->nAYCurrentRegister[AY8913_DEVICE_B]) & (r6522.GetReg(SY6522::rDDRA) ^ 0xff)));
}
}
break;
@ -379,8 +382,8 @@ void MockingboardCard::AY8913_Write(BYTE subunit, BYTE ay, BYTE value)
state = nAYFunc;
if (state == AY_INACTIVE && m_phasorEnable) // Phasor(even in MB mode) will read PortA inputs as high.
r6522.UpdatePortAForHiZ(); // Float high any PortA input bits (GH#1193)
if (state == AY_INACTIVE) // Mockingboard or Phasor(any mode) will read PortA inputs as high.
pMB->isDrivingBus = false;
}
//-----------------------------------------------------------------------------
@ -638,10 +641,10 @@ BYTE MockingboardCard::IOReadInternal(WORD PC, WORD nAddr, BYTE bWrite, BYTE nVa
BYTE nRes = 0;
if (CS & 1)
nRes |= m_MBSubUnit[SY6522_DEVICE_A].sy6522.Read(nAddr & 0xf);
nRes |= m_MBSubUnit[SY6522_DEVICE_A].sy6522.Read(nAddr & 0xf, m_MBSubUnit[SY6522_DEVICE_A].isDrivingBus);
if (CS & 2)
nRes |= m_MBSubUnit[SY6522_DEVICE_B].sy6522.Read(nAddr & 0xf);
nRes |= m_MBSubUnit[SY6522_DEVICE_B].sy6522.Read(nAddr & 0xf, m_MBSubUnit[SY6522_DEVICE_B].isDrivingBus);
bool bAccessedDevice = (CS & 3) ? true : false;
@ -668,7 +671,7 @@ BYTE MockingboardCard::IOReadInternal(WORD PC, WORD nAddr, BYTE bWrite, BYTE nVa
// NB. Mockingboard: SSI263.bit7 not readable (TODO: check this with real h/w)
const BYTE subunit = QueryType() == CT_SDMusic ? SY6522_DEVICE_A : !(nAddr & 0x80) ? SY6522_DEVICE_A : SY6522_DEVICE_B;
const BYTE reg = nAddr & 0xf;
return m_MBSubUnit[subunit].sy6522.Read(reg);
return m_MBSubUnit[subunit].sy6522.Read(reg, m_MBSubUnit[subunit].isDrivingBus);
}
//-----------------------------------------------------------------------------
@ -1151,7 +1154,8 @@ UINT MockingboardCard::AY8910_LoadSnapshot(YamlLoadHelper& yamlLoadHelper, BYTE
// "Chip Select A" + "Chip Select B"
// "Reg Address Latch Valid A" + "Reg Address Latch Valid B"
// Changed at AppleWin 1.30.14
const UINT kUNIT_VERSION = 10;
//11: Added: "Bus Driven by AY"
const UINT kUNIT_VERSION = 11;
#define SS_YAML_KEY_MB_UNIT "Unit"
#define SS_YAML_KEY_AY_CURR_REG "AY Current Register"
@ -1167,6 +1171,7 @@ const UINT kUNIT_VERSION = 10;
#define SS_YAML_KEY_SPEECH_IRQ "Speech IRQ Pending" // v8: deprecated
#define SS_YAML_KEY_TIMER1_ACTIVE "Timer1 Active" // v8: move to 6522 sub-unit
#define SS_YAML_KEY_TIMER2_ACTIVE "Timer2 Active" // v8: move to 6522 sub-unit
#define SS_YAML_KEY_BUS_DRIVEN "Bus Driven by AY"
#define SS_YAML_KEY_PHASOR_UNIT "Unit"
#define SS_YAML_KEY_PHASOR_CLOCK_SCALE_FACTOR "Clock Scale Factor" // v6: deprecated
@ -1231,6 +1236,7 @@ void MockingboardCard::SaveSnapshot(YamlSaveHelper& yamlSaveHelper)
yamlSaveHelper.SaveHexUint8(SS_YAML_KEY_AY_CURR_REG, pMB->nAYCurrentRegister[0]); // save all 8 bits (even though top 4 bits should be 0)
yamlSaveHelper.SaveBool(SS_YAML_KEY_CS_A, pMB->isChipSelected[0]);
yamlSaveHelper.SaveBool(SS_YAML_KEY_LATCH_ADDR_VALID_A, pMB->isAYLatchedAddressValid[0]);
yamlSaveHelper.SaveBool(SS_YAML_KEY_BUS_DRIVEN, pMB->isDrivingBus);
}
}
@ -1297,6 +1303,10 @@ bool MockingboardCard::LoadSnapshot(YamlLoadHelper& yamlLoadHelper, UINT version
pMB->isAYLatchedAddressValid[0] = yamlLoadHelper.LoadBool(SS_YAML_KEY_LATCH_ADDR_VALID_A);
}
pMB->isDrivingBus = (pMB->state[0] == AY_READ);
if (version >= 11)
pMB->isDrivingBus = yamlLoadHelper.LoadBool(SS_YAML_KEY_BUS_DRIVEN);
yamlLoadHelper.PopMap();
}
@ -1336,6 +1346,8 @@ void MockingboardCard::Phasor_SaveSnapshot(YamlSaveHelper& yamlSaveHelper)
yamlSaveHelper.SaveBool(SS_YAML_KEY_CS_B, pMB->isChipSelected[1]);
yamlSaveHelper.SaveBool(SS_YAML_KEY_LATCH_ADDR_VALID_A, pMB->isAYLatchedAddressValid[0]);
yamlSaveHelper.SaveBool(SS_YAML_KEY_LATCH_ADDR_VALID_B, pMB->isAYLatchedAddressValid[1]);
yamlSaveHelper.SaveBool(SS_YAML_KEY_BUS_DRIVEN, pMB->isDrivingBus);
}
}
@ -1430,6 +1442,10 @@ bool MockingboardCard::Phasor_LoadSnapshot(YamlLoadHelper& yamlLoadHelper, UINT
pMB->isAYLatchedAddressValid[1] = yamlLoadHelper.LoadBool(SS_YAML_KEY_LATCH_ADDR_VALID_B);
}
pMB->isDrivingBus = (pMB->state[0] == AY_READ || pMB->state[1] == AY_READ);
if (version >= 11)
pMB->isDrivingBus = yamlLoadHelper.LoadBool(SS_YAML_KEY_BUS_DRIVEN);
yamlLoadHelper.PopMap();
}

View File

@ -87,6 +87,7 @@ private:
MockingboardUnitState_e state[NUM_AY8913_PER_SUBUNIT]; // AY's PSG function
bool isAYLatchedAddressValid[NUM_AY8913_PER_SUBUNIT];
bool isChipSelected[NUM_AY8913_PER_SUBUNIT];
bool isDrivingBus;
MB_SUBUNIT(UINT slot, SS_CARDTYPE type) : sy6522(slot, type == CT_MegaAudio), ssi263(slot)
{
@ -102,6 +103,7 @@ private:
isAYLatchedAddressValid[0] = isAYLatchedAddressValid[1] = false; // after AY reset
isChipSelected[0] = type == CT_Phasor ? false : true; // Only Phasor is false, all other MB variants are true
isChipSelected[1] = false;
isDrivingBus = false;
}
};