Sprinter/mame
2
0
Fork 0
mirror of https://github.com/holub/mame synced 2025-10-05 08:41:31 +03:00
Code Issues Actions 3 Packages Projects Releases Wiki Activity

electron: Set CPU clock 2MHz/1MHz according to ROM/RAM access.

Browse Source
This commit is contained in:
Nigel Barnes 2018-03-21 13:00:19 +00:00
parent 079522fe67
commit f22c5609ba
3 changed files with 64 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
src/mame/drivers/electron.cpp
View File

@ -90,9 +90,9 @@ PALETTE_INIT_MEMBER(electron_state, electron)
void electron_state::electron_mem(address_map &map)
{
map(0x0000, 0x7fff).rw(this, FUNC(electron_state::electron_mem_r), FUNC(electron_state::electron_mem_w)); /* 32KB of RAM */
map(0x8000, 0xbfff).rw(this, FUNC(electron_state::electron_paged_r), FUNC(electron_state::electron_paged_w)); /* Banked ROM pages */
map(0xc000, 0xffff).rom().region("mos", 0).w(this, FUNC(electron_state::electron_mos_w)); /* OS ROM */
map(0x0000, 0x7fff).rw(this, FUNC(electron_state::electron_mem_r), FUNC(electron_state::electron_mem_w)); /* 32KB of RAM */
map(0x8000, 0xbfff).rw(this, FUNC(electron_state::electron_paged_r), FUNC(electron_state::electron_paged_w)); /* Banked ROM pages */
map(0xc000, 0xffff).rw(this, FUNC(electron_state::electron_mos_r), FUNC(electron_state::electron_mos_w)); /* OS ROM */
map(0xfc00, 0xfcff).rw(this, FUNC(electron_state::electron_fred_r), FUNC(electron_state::electron_fred_w)); /* FRED */
map(0xfd00, 0xfdff).rw(this, FUNC(electron_state::electron_jim_r), FUNC(electron_state::electron_jim_w)); /* JIM */
map(0xfe00, 0xfeff).rw(this, FUNC(electron_state::electron_sheila_r), FUNC(electron_state::electron_sheila_w)); /* SHEILA */

23
src/mame/includes/electron.h
View File

@ -39,15 +39,17 @@ public:
};
electron_state(const machine_config &mconfig, device_type type, const char *tag)
: driver_device(mconfig, type, tag),
m_maincpu(*this, "maincpu"),
m_screen(*this, "screen"),
m_cassette(*this, "cassette"),
m_beeper(*this, "beeper"),
m_region_basic(*this, "basic"),
m_keybd(*this, "LINE.%u", 0),
m_exp(*this, "exp"),
m_ram(*this, RAM_TAG)
: driver_device(mconfig, type, tag)
, m_maincpu(*this, "maincpu")
, m_screen(*this, "screen")
, m_cassette(*this, "cassette")
, m_beeper(*this, "beeper")
, m_region_basic(*this, "basic")
, m_region_mos(*this, "mos")
, m_keybd(*this, "LINE.%u", 0)
, m_exp(*this, "exp")
, m_ram(*this, RAM_TAG)
, m_mrb(*this, "MRB")
{ }
/* ULA context */
@ -88,6 +90,7 @@ public:
DECLARE_WRITE8_MEMBER(electron_mem_w);
DECLARE_READ8_MEMBER(electron_paged_r);
DECLARE_WRITE8_MEMBER(electron_paged_w);
DECLARE_READ8_MEMBER(electron_mos_r);
DECLARE_WRITE8_MEMBER(electron_mos_w);
DECLARE_READ8_MEMBER(electron_fred_r);
DECLARE_WRITE8_MEMBER(electron_fred_w);
@ -111,9 +114,11 @@ public:
required_device<cassette_image_device> m_cassette;
required_device<beep_device> m_beeper;
required_memory_region m_region_basic;
required_memory_region m_region_mos;
required_ioport_array<14> m_keybd;
required_device<electron_expansion_slot_device> m_exp;
required_device<ram_device> m_ram;
optional_ioport m_mrb;
inline uint8_t read_vram( uint16_t addr );
inline void electron_plot_pixel(bitmap_ind16 &bitmap, int x, int y, uint32_t color);
void electron_interrupt_handler(int mode, int interrupt);

47
src/mame/machine/electron.cpp
View File

@ -144,12 +144,18 @@ TIMER_CALLBACK_MEMBER(electron_state::electron_tape_timer_handler)
READ8_MEMBER(electron_state::electron_mem_r)
{
/* The processor will run at 1MHz during an access cycle to the RAM */
m_maincpu->set_clock_scale(0.5f);
//waitforramsync();
return m_ram->read(offset);
}
WRITE8_MEMBER(electron_state::electron_mem_w)
{
/* The processor will run at 1MHz during an access cycle to the RAM */
m_maincpu->set_clock_scale(0.5f);
//waitforramsync();
m_ram->write(offset, data);
}
@ -175,6 +181,9 @@ READ8_MEMBER(electron_state::electron_paged_r)
uint8_t data = 0;
/* The processor will run at 2MHz during an access cycle to the ROM */
m_maincpu->set_clock_scale(1.0f);
switch (m_ula.rompage)
{
case 8:
@ -205,17 +214,34 @@ READ8_MEMBER(electron_state::electron_paged_r)
WRITE8_MEMBER(electron_state::electron_paged_w)
{
/* The processor will run at 2MHz during an access cycle to the ROM */
m_maincpu->set_clock_scale(1.0f);
m_exp->expbus_w(space, 0x8000 + offset, data);
}
READ8_MEMBER(electron_state::electron_mos_r)
{
/* The processor will run at 2MHz during an access cycle to the ROM */
m_maincpu->set_clock_scale(1.0f);
return m_region_mos->base()[offset & 0x3fff];
}
WRITE8_MEMBER(electron_state::electron_mos_w)
{
/* The processor will run at 2MHz during an access cycle to the ROM */
m_maincpu->set_clock_scale(1.0f);
logerror("MOS: write %04x %02x\n", offset + 0xc000, data);
m_exp->expbus_w(space, 0xc000 + offset, data);
}
READ8_MEMBER(electron_state::electron_fred_r)
{
/* The processor will run at 2MHz during an access cycle to the ROM */
m_maincpu->set_clock_scale(1.0f);
/* The Issue 4 ULA returns data from OS ROM, whereas Issue 6 ULA will return 0xff */
//logerror("FRED: read fc%02x\n", offset);
return m_exp->expbus_r(space, 0xfc00 + offset, 0xff);
@ -223,12 +249,24 @@ READ8_MEMBER(electron_state::electron_fred_r)
WRITE8_MEMBER(electron_state::electron_fred_w)
{
/* The processor will run at 2MHz during an access cycle to the ROM */
m_maincpu->set_clock_scale(1.0f);
//logerror("FRED: write fc%02x\n", offset);
m_exp->expbus_w(space, 0xfc00 + offset, data);
/* Master RAM Board */
if (offset == 0x7f && m_mrb.read_safe(0))
{
}
}
READ8_MEMBER(electron_state::electron_jim_r)
{
/* The processor will run at 2MHz during an access cycle to the ROM */
m_maincpu->set_clock_scale(1.0f);
/* The Issue 4 ULA returns data from OS ROM, whereas Issue 6 ULA will return 0xff */
//logerror("JIM: read fd%02x\n", offset);
return m_exp->expbus_r(space, 0xfd00 + offset, 0xff);
@ -236,12 +274,18 @@ READ8_MEMBER(electron_state::electron_jim_r)
WRITE8_MEMBER(electron_state::electron_jim_w)
{
/* The processor will run at 2MHz during an access cycle to the ROM */
m_maincpu->set_clock_scale(1.0f);
//logerror("JIM: write fd%02x\n", offset);
m_exp->expbus_w(space, 0xfd00 + offset, data);
}
READ8_MEMBER(electron_state::electron_sheila_r)
{
/* The processor will run at 2MHz during an access cycle to the ROM */
m_maincpu->set_clock_scale(1.0f);
/* The Issue 4 ULA returns data from OS ROM, whereas Issue 6 ULA will return 0xfe */
uint8_t data = 0xff;
@ -267,6 +311,9 @@ static const uint16_t electron_screen_base[8] = { 0x3000, 0x3000, 0x3000, 0x4000
WRITE8_MEMBER(electron_state::electron_sheila_w)
{
/* The processor will run at 2MHz during an access cycle to the ROM */
m_maincpu->set_clock_scale(1.0f);
m_exp->expbus_w(space, 0xfe00 + offset, data);
int i = electron_palette_offset[(( offset >> 1 ) & 0x03)];