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-rw-r--r--src/devices/machine/z8536.cpp16
-rw-r--r--src/devices/machine/z8536.h9
2 files changed, 17 insertions, 8 deletions
diff --git a/src/devices/machine/z8536.cpp b/src/devices/machine/z8536.cpp
index fe1a91ff631..6d4fe6825c5 100644
--- a/src/devices/machine/z8536.cpp
+++ b/src/devices/machine/z8536.cpp
@@ -1041,19 +1041,19 @@ u8 z8536_device::read(offs_t offset)
{
switch (offset & 0x03)
{
- case 0:
+ case EXT_PORT_C:
data = read_register(PORT_C_DATA);
break;
- case 1:
+ case EXT_PORT_B:
data = read_register(PORT_B_DATA);
break;
- case 2:
+ case EXT_PORT_A:
data = read_register(PORT_A_DATA);
break;
- case 3:
+ case EXT_CONTROL:
// state 0 or state 1: read data
data = read_register(m_pointer);
@@ -1107,19 +1107,19 @@ void z8536_device::write(offs_t offset, u8 data)
{
switch (offset & 0x03)
{
- case 0:
+ case EXT_PORT_C:
write_register(PORT_C_DATA, data);
break;
- case 1:
+ case EXT_PORT_B:
write_register(PORT_B_DATA, data);
break;
- case 2:
+ case EXT_PORT_A:
write_register(PORT_A_DATA, data);
break;
- case 3:
+ case EXT_CONTROL:
if (m_state0)
{
// state 0: write pointer
diff --git a/src/devices/machine/z8536.h b/src/devices/machine/z8536.h
index 487d9b771e0..e307ea09069 100644
--- a/src/devices/machine/z8536.h
+++ b/src/devices/machine/z8536.h
@@ -443,6 +443,15 @@ protected:
virtual void z80daisy_irq_reti() override;
private:
+ // direct external access to ports
+ enum
+ {
+ EXT_PORT_C = 0,
+ EXT_PORT_B,
+ EXT_PORT_A,
+ EXT_CONTROL
+ };
+
// control state machine
bool m_state0;
u8 m_pointer;