Sprinter/mame
2
0
Fork 0
mirror of https://github.com/holub/mame synced 2025-05-22 21:58:57 +03:00
Code Issues Actions 3 Packages Projects Releases Wiki Activity

fix port C-lower mask in port A mode 2 + fix obvious bug with port C-lower output

Browse Source
This commit is contained in:
Michaël Banaan Ananas 2012-05-20 12:52:38 +00:00
parent 932910a75e
commit 5921ca09af
1 changed files with 22 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
src/emu/machine/i8255.c
View File

@ -417,6 +417,7 @@ UINT8 i8255_device::read_pc()
{
UINT8 data = 0;
UINT8 mask = 0;
UINT8 b_mask = 0x0f;
// PC upper
switch (group_mode(GROUP_A))
@ -452,6 +453,7 @@ UINT8 i8255_device::read_pc()
break;
case MODE_2:
b_mask = 0x07;
data |= m_intr[PORT_A] ? 0x08 : 0x00;
data |= m_inte2 ? 0x10 : 0x00;
data |= m_ibf[PORT_A] ? 0x20 : 0x00;
@ -467,12 +469,12 @@ UINT8 i8255_device::read_pc()
if (port_c_lower_mode() == MODE_OUTPUT)
{
// read data from output latch
data |= m_output[PORT_C] & 0x0f;
data |= m_output[PORT_C] & b_mask;
}
else
{
// read data from port
mask |= 0x0f;
mask |= b_mask;
}
break;
@ -568,21 +570,18 @@ void i8255_device::write_pc(UINT8 data)
{
int changed = 0;
if (group_mode(GROUP_A) == MODE_0)
// PC upper
if (group_mode(GROUP_A) == MODE_0 && port_c_upper_mode() == MODE_OUTPUT)
{
// PC upper
if (port_c_upper_mode() == MODE_OUTPUT)
{
m_output[PORT_C] = (data & 0xf0) | (m_output[PORT_C] & 0x0f);
changed = 1;
}
m_output[PORT_C] = (data & 0xf0) | (m_output[PORT_C] & 0x0f);
changed = 1;
}
// PC lower
if (port_c_lower_mode() == MODE_OUTPUT)
{
m_output[PORT_C] = (m_output[PORT_C] & 0xf0) | (data & 0x0f);
changed = 1;
}
// PC lower
if (group_mode(GROUP_B) == MODE_0 && port_c_lower_mode() == MODE_OUTPUT)
{
m_output[PORT_C] = (m_output[PORT_C] & 0xf0) | (data & 0x0f);
changed = 1;
}
if (changed)
@ -600,6 +599,7 @@ void i8255_device::output_pc()
{
UINT8 data = 0;
UINT8 mask = 0;
UINT8 b_mask = 0x0f;
// PC upper
switch (group_mode(GROUP_A))
@ -632,6 +632,7 @@ void i8255_device::output_pc()
break;
case MODE_2:
b_mask = 0x07;
data |= m_intr[PORT_A] ? 0x08 : 0x00;
data |= m_ibf[PORT_A] ? 0x20 : 0x00;
data |= m_obf[PORT_A] ? 0x80 : 0x00;
@ -644,12 +645,12 @@ void i8255_device::output_pc()
case MODE_0:
if (port_c_lower_mode() == MODE_OUTPUT)
{
mask |= 0x0f;
mask |= b_mask;
}
else
{
// TTL inputs float high
data |= 0x0f;
data |= b_mask;
}
break;
@ -753,6 +754,7 @@ void i8255_device::set_pc_bit(int bit, int state)
case 3: set_intr(PORT_A, state); break;
case 6: set_inte(PORT_A, state); break;
case 7: set_obf(PORT_A, state); break;
default: break;
}
}
else
@ -762,6 +764,7 @@ void i8255_device::set_pc_bit(int bit, int state)
case 3: set_intr(PORT_A, state); break;
case 4: set_inte(PORT_A, state); break;
case 5: set_ibf(PORT_A, state); break;
default: break;
}
}
break;
@ -774,6 +777,7 @@ void i8255_device::set_pc_bit(int bit, int state)
case 5: set_ibf(PORT_A, state); break;
case 6: set_inte1(state); break;
case 7: set_obf(PORT_A, state); break;
default: break;
}
break;
}
@ -790,6 +794,7 @@ void i8255_device::set_pc_bit(int bit, int state)
set_ibf(PORT_B, state);
break;
case 2: set_inte(PORT_B, state); break;
default: break;
}
}