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Phasor: AY RESET resets both AYs attached to 6522 regardless of Phasor mode & CS bits. ()

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This commit is contained in:
tomcw 2023-09-07 21:40:13 +01:00
parent cd2f29b723
commit be427a6a30
2 changed files with 108 additions and 91 deletions

48
source/Mockingboard.cpp

@ -185,13 +185,17 @@ void MockingboardCard::Get6522IrqDescription(std::string& desc)
//
// AFAICT, inputs to the Phasor GAL are:
// . ORB.b4:3 = Chip Select (CS) for AY1 & AY2 (active low)
// . ORB.b2:0 = PSG Function (RESET, INACTIVE, READ, WRITE, LATCH) [Or since LATCH=%111, then maybe a 3-input AND: b2.b1.b0 -> GAL?]
// .(ORB.b2 : AY /RESET is not an input - see below)
// . ORB.b1:0 = PSG Function (INACTIVE, READ, WRITE, LATCH) [Or since LATCH=%11, then maybe a 2-input AND: b1.b0 -> GAL?]
// . Phasor mode (Mockingboard, Echo+, Phasor-native)
// . Slot inputs (address, reset, etc)
// And outputs from the GAL are:
// . GAL CS' for AY1 & AY2 (not just passed-through, but dependent on PSG Function)
// (Not PSG Function - probably just passed-through from 6522 to the chip-selected AY-3-8913's)
//
// Not an input to Phasor GAL:
// . ORB.b2 = AY /RESET (NB. not a PSG Function). Directly connected to AY's /RESET pin (or in Phasor's case: both AYs' /RESET pins).
//
// In Phasor-native mode, GAL logic:
// . AY2 LATCH func selects AY2 and AY1; sets latch addr for AY2 and AY1
// . AY1 LATCH func selects AY1; deselects AY2; sets latch addr for AY1
@ -233,44 +237,57 @@ void MockingboardCard::WriteToORB(BYTE subunit, BYTE subunitForAY/*=0*/)
if (m_phasorMode == PH_EchoPlus)
subunit = SY6522_DEVICE_B;
if ((value & 4) == 0)
{
AY8913_Reset(subunit);
return;
}
// NB. For PH_Phasor, when selecting *both* AYs, then order matters: first do AY8913_DEVICE_A then AY8913_DEVICE_B
// Reason: from GAL logic: 'AY1 LATCH func' deselects AY2, then 'AY2 LATCH func' selects AY2 and AY1. (And we want both selected)
if (nAY_CS & kAY1)
AY8910_Write(subunit, AY8913_DEVICE_A, value);
AY8913_Write(subunit, AY8913_DEVICE_A, value);
if (nAY_CS & kAY2)
AY8910_Write(subunit, AY8913_DEVICE_B, value);
AY8913_Write(subunit, AY8913_DEVICE_B, value);
if (nAY_CS == 0)
m_MBSubUnit[subunit].sy6522.UpdatePortAForHiZ();
}
else
{
if ((value & 4) == 0)
{
AY8913_Reset(subunit);
return;
}
if (QueryType() == CT_SDMusic)
AY8910_Write(subunitForAY, AY8913_DEVICE_A, value);
AY8913_Write(subunitForAY, AY8913_DEVICE_A, value);
else
AY8910_Write(subunit, AY8913_DEVICE_A, value);
AY8913_Write(subunit, AY8913_DEVICE_A, value);
}
#endif
}
//-----------------------------------------------------------------------------
void MockingboardCard::AY8910_Write(BYTE subunit, BYTE ay, BYTE value)
void MockingboardCard::AY8913_Reset(BYTE subunit)
{
AY8910_reset(subunit, AY8913_DEVICE_A);
if (QueryType() == CT_Phasor)
AY8910_reset(subunit, AY8913_DEVICE_B); // GH#1197: Reset both AYs regardless of Phasor mode & chip-select bits
m_MBSubUnit[subunit].Reset(QueryType());
}
void MockingboardCard::AY8913_Write(BYTE subunit, BYTE ay, BYTE value)
{
m_regAccessedFlag = true;
MB_SUBUNIT* pMB = &m_MBSubUnit[subunit];
SY6522& r6522 = (QueryType() != CT_SDMusic) ? pMB->sy6522 : m_MBSubUnit[0].sy6522;
if ((value & 4) == 0)
{
// RESET: Reset AY8910 only
AY8910_reset(subunit, ay);
pMB->Reset(QueryType());
}
else
{
// Determine the AY8910 inputs
// Determine the AY8913 inputs
int nBDIR = (value & 2) ? 1 : 0;
const int nBC2 = 1; // Hardwired to +5V
int nBC1 = value & 1;
@ -364,7 +381,6 @@ void MockingboardCard::AY8910_Write(BYTE subunit, BYTE ay, BYTE value)
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)
}
}
//-----------------------------------------------------------------------------

3
source/Mockingboard.h

@ -106,7 +106,8 @@ private:
};
void WriteToORB(BYTE subunit, BYTE subunitForAY=0);
void AY8910_Write(BYTE subunit, BYTE ay, BYTE value);
void AY8913_Reset(BYTE subunit);
void AY8913_Write(BYTE subunit, BYTE ay, BYTE value);
void UpdateIFRandIRQ(MB_SUBUNIT* pMB, BYTE clr_mask, BYTE set_mask);
void Phasor_SaveSnapshot(YamlSaveHelper& yamlSaveHelper);