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Fixed the second PSG addressing on the ECHO+ (#9330)

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The ECHO+ uses a single VIA to address two PSGs. The BC2 lines of the PSGs are connected to PB3 and PB4 respectively. Both PSGs are reset through PB2.
This commit is contained in:
cybernesto 2022-02-22 20:39:13 +01:00 committed by GitHub
parent 89baa1de94
commit dc7d590ae2
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GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 8 additions and 19 deletions
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27
src/devices/bus/a2bus/a2mockingboard.cpp
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@ -137,9 +137,6 @@ protected:
virtual void write_cnxx(u8 offset, u8 data) override; virtual void write_cnxx(u8 offset, u8 data) override;
required_device<tms5220_device> m_tms; required_device<tms5220_device> m_tms;
private:
u8 m_last_cnxx_addr;
}; };
//------------------------------------------------- //-------------------------------------------------
@ -294,7 +291,6 @@ u8 a2bus_ayboard_device::read_cnxx(u8 offset)
u8 a2bus_echoplus_device::read_cnxx(u8 offset) u8 a2bus_echoplus_device::read_cnxx(u8 offset)
{ {
m_last_cnxx_addr = offset;
return m_via1->read(offset & 0xf); return m_via1->read(offset & 0xf);
} }
@ -348,7 +344,6 @@ void a2bus_ayboard_device::write_cnxx(u8 offset, u8 data)
void a2bus_echoplus_device::write_cnxx(u8 offset, u8 data) void a2bus_echoplus_device::write_cnxx(u8 offset, u8 data)
{ {
m_last_cnxx_addr = offset;
m_via1->write(offset & 0xf, data); m_via1->write(offset & 0xf, data);
} }
@ -437,13 +432,14 @@ void a2bus_ayboard_device::via1_out_b(u8 data)
void a2bus_echoplus_device::via1_out_b(u8 data) void a2bus_echoplus_device::via1_out_b(u8 data)
{ {
if (!(m_last_cnxx_addr & 0x80)) if (!BIT(data, 2))
{ {
if (!BIT(data, 2)) m_ay1->reset_w();
{ m_ay2->reset_w();
m_ay1->reset_w(); }
} else
else {
if (BIT(data, 3)) // BC2_1=1 (PSG1 active)
{ {
switch (data & 3) switch (data & 3)
{ {
@ -463,14 +459,7 @@ void a2bus_echoplus_device::via1_out_b(u8 data)
break; break;
} }
} }
} if (BIT(data, 4)) // BC2_2_=1 (PSG2 active)
else
{
if (!BIT(data, 2))
{
m_ay2->reset_w();
}
else
{ {
switch (data & 3) switch (data & 3)
{ {