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Code Issues Projects Releases Wiki Activity

Phasor: support Echo+ mode (#1183)

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This commit is contained in:
tomcw 2023-02-19 16:38:06 +00:00
parent fd8ed23b56
commit bcdaa3e1c1
1 changed files with 31 additions and 12 deletions
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43
source/Mockingboard.cpp
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@ -58,6 +58,7 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#include "SSI263.h"
#define DBG_MB_SS_CARD 0 // NB. From UI, select Mockingboard (not Phasor)
#define DBG_SUPPORT_ECHOPLUS 0 // Allow Phasor (in Echo+ mode) to pass the TMS5220 detection used by Echo+ disk
//---------------------------------------------------------------------------
@ -197,13 +198,25 @@ void MockingboardCard::WriteToORB(BYTE subunit)
{
const int kAY0 = 2; // bit4=0 (active low) selects the 1st AY8913, ie. the only AY8913 in Mockingboard mode (confirmed on real Phasor h/w)
const int kAY1 = 1; // bit3=0 (active low) selects the 2nd AY8913 attached to this 6522 (unavailable in Mockingboard mode)
int nAY_CS = (m_phasorMode == PH_Phasor) ? (~(value >> 3) & 3) : kAY0;
if (nAY_CS & kAY0)
AY8910_Write(subunit, AY8913_DEVICE_A, value);
if (m_phasorMode == PH_EchoPlus)
{
int nAY_CS = (value >> 3) & 3;
if (nAY_CS & kAY0)
AY8910_Write(0, AY8913_DEVICE_A, value);
if (nAY_CS & kAY1)
AY8910_Write(subunit, AY8913_DEVICE_B, value);
if (nAY_CS & kAY1)
AY8910_Write(1, AY8913_DEVICE_A, value);
}
else
{
int nAY_CS = (m_phasorMode == PH_Phasor) ? (~(value >> 3) & 3) : kAY0;
if (nAY_CS & kAY0)
AY8910_Write(subunit, AY8913_DEVICE_A, value);
if (nAY_CS & kAY1)
AY8910_Write(subunit, AY8913_DEVICE_B, value);
}
}
else
{
@ -218,6 +231,7 @@ void MockingboardCard::AY8910_Write(BYTE subunit, BYTE ay, BYTE value)
{
m_regAccessedFlag = true;
MB_SUBUNIT* pMB = &m_MBSubUnit[subunit];
SY6522& r6522 = (m_phasorEnable && m_phasorMode == PH_EchoPlus) ? m_MBSubUnit[SY6522_DEVICE_B].sy6522 : pMB->sy6522;
if ((value & 4) == 0)
{
@ -235,9 +249,9 @@ void MockingboardCard::AY8910_Write(BYTE subunit, BYTE ay, BYTE value)
MockingboardUnitState_e& state = (ay == AY8913_DEVICE_A) ? pMB->state : pMB->stateB; // GH#659
#if _DEBUG
if (!m_phasorEnable)
if (!m_phasorEnable || m_phasorMode != PH_Phasor)
_ASSERT(ay == AY8913_DEVICE_A);
if (nAYFunc == AY_WRITE || nAYFunc == AY_LATCH)
if (nAYFunc == AY_READ || nAYFunc == AY_WRITE || nAYFunc == AY_LATCH)
_ASSERT(state == AY_INACTIVE);
#endif
@ -250,13 +264,13 @@ void MockingboardCard::AY8910_Write(BYTE subunit, BYTE ay, BYTE value)
case AY_READ: // 5: READ FROM PSG (need to set DDRA to input)
if (m_phasorEnable && m_phasorMode == PH_EchoPlus)
pMB->sy6522.SetRegORA( 0xff & (pMB->sy6522.GetReg(SY6522::rDDRA) ^ 0xff) ); // Phasor (Echo+ mode) doesn't support reading AY8913s - it just reads 1's for the input bits
r6522.SetRegORA( 0xff & (r6522.GetReg(SY6522::rDDRA) ^ 0xff) ); // Phasor (Echo+ mode) doesn't support reading AY8913s - it just reads 1's for the input bits
else
pMB->sy6522.SetRegORA( AYReadReg(subunit, ay, pMB->nAYCurrentRegister) & (pMB->sy6522.GetReg(SY6522::rDDRA) ^ 0xff) );
r6522.SetRegORA( AYReadReg(subunit, ay, pMB->nAYCurrentRegister) & (r6522.GetReg(SY6522::rDDRA) ^ 0xff) );
break;
case AY_WRITE: // 6: WRITE TO PSG
_AYWriteReg(subunit, ay, pMB->nAYCurrentRegister, pMB->sy6522.GetReg(SY6522::rORA));
_AYWriteReg(subunit, ay, pMB->nAYCurrentRegister, r6522.GetReg(SY6522::rORA));
break;
case AY_LATCH: // 7: LATCH ADDRESS
@ -264,8 +278,8 @@ void MockingboardCard::AY8910_Write(BYTE subunit, BYTE ay, BYTE value)
// Selecting an unused register number above 0x0f puts the AY into a state where
// any values written to the data/address bus are ignored, but can be read back
// within a few tens of thousands of cycles before they decay to zero.
if (pMB->sy6522.GetReg(SY6522::rORA) <= 0x0F)
pMB->nAYCurrentRegister = pMB->sy6522.GetReg(SY6522::rORA) & 0x0F;
if (r6522.GetReg(SY6522::rORA) <= 0x0F)
pMB->nAYCurrentRegister = r6522.GetReg(SY6522::rORA) & 0x0F;
// else Pro-Mockingboard (clone from HK)
break;
}
@ -715,6 +729,11 @@ BYTE MockingboardCard::PhasorIOInternal(WORD PC, WORD nAddr, BYTE bWrite, BYTE n
for (UINT i = 0; i < NUM_SSI263; i++)
m_MBSubUnit[i].ssi263.SetCardMode(m_phasorMode);
#if DBG_SUPPORT_ECHOPLUS
if (m_phasorMode == PH_EchoPlus && (nAddr & 0xf) == 0)
return 0x1f; // for TMS5220 detection
#endif
return MemReadFloatingBus(nExecutedCycles);
}