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author Roman Donchenko <rdonchen@outlook.com>2024-10-13 17:29:10 +0300
committer GitHub <noreply@github.com>2024-10-14 01:29:10 +1100
commitec9aec11be23ad7eda6fc52d38fdf90ca6a484e2 (patch)
tree72a47d22984d1f328aee3527e9e9c85f52f2abea /src
parentb49a1dc0102a3add9371f5ae5b610ab6877b32c1 (diff)
bus/a2bus/suprterminal.cpp: Allow mapping control via C0Bx reads. (#12876)
C0B2, C0B4 and C0B6 react to both reads and writes according to the manual.
Diffstat (limited to 'src')
-rw-r--r--src/devices/bus/a2bus/suprterminal.cpp52
1 files changed, 34 insertions, 18 deletions
diff --git a/src/devices/bus/a2bus/suprterminal.cpp b/src/devices/bus/a2bus/suprterminal.cpp
index 0cac42964b2..7f29899d0ec 100644
--- a/src/devices/bus/a2bus/suprterminal.cpp
+++ b/src/devices/bus/a2bus/suprterminal.cpp
@@ -75,6 +75,8 @@ private:
std::unique_ptr<u8[]> m_fontram;
// u8 m_fontram[0x400];
bool m_bRasterRAM, m_bCharBank1, m_bC800IsRAM;
+
+ void access_c0nx(u8 offset);
};
//-------------------------------------------------
@@ -145,18 +147,7 @@ u8 a2bus_suprterminal_device::read_cnxx(u8 offset)
return m_rom[offset+0x300];
}
-u8 a2bus_suprterminal_device::read_c0nx(u8 offset)
-{
- switch (offset)
- {
- case 9:
- return m_crtc->register_r();
- }
-
- return 0xff;
-}
-
-void a2bus_suprterminal_device::write_c0nx(u8 offset, u8 data)
+void a2bus_suprterminal_device::access_c0nx(u8 offset)
{
switch (offset)
{
@@ -173,14 +164,39 @@ void a2bus_suprterminal_device::write_c0nx(u8 offset, u8 data)
case 6:
m_bCharBank1 ^= 1;
break;
+ }
+}
- case 8:
- m_crtc->address_w(data);
- break;
+u8 a2bus_suprterminal_device::read_c0nx(u8 offset)
+{
+ if (offset < 8)
+ {
+ if (!machine().side_effects_disabled())
+ {
+ access_c0nx(offset);
+ }
+ }
+ else if (offset == 9)
+ {
+ return m_crtc->register_r();
+ }
- case 9:
- m_crtc->register_w(data);
- break;
+ return 0xff;
+}
+
+void a2bus_suprterminal_device::write_c0nx(u8 offset, u8 data)
+{
+ if (offset < 8)
+ {
+ access_c0nx(offset);
+ }
+ else if (offset == 8)
+ {
+ m_crtc->address_w(data);
+ }
+ else if (offset == 9)
+ {
+ m_crtc->register_w(data);
}
}