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smc777: Fix ROM/RAM register change; use addressable latch device

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This commit is contained in:
AJR 2024-09-07 22:59:49 -04:00
parent 425573a0cb
commit b72023282b
1 changed files with 67 additions and 26 deletions
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93
src/mame/sony/smc777.cpp
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@ -25,6 +25,7 @@
#include "cpu/mcs48/mcs48.h"
#include "imagedev/floppy.h"
#include "imagedev/snapquik.h"
#include "machine/74259.h"
#include "machine/timer.h"
#include "machine/wd_fdc.h"
#include "softlist_dev.h"
@ -66,6 +67,7 @@ public:
, m_crtc(*this, "crtc")
, m_fdc(*this, "fdc")
, m_floppy(*this, "fdc:%u", 0U)
, m_ioctrl(*this, "ioctrl")
, m_beeper(*this, "beeper")
, m_gfxdecode(*this, "gfxdecode")
, m_palette(*this, "palette")
@ -94,6 +96,14 @@ private:
uint8_t io_status_1c_r();
uint8_t io_status_1d_r();
void io_control_w(uint8_t data);
void raminh_w(int state);
void vsup_w(int state);
void screen_lines_w(int state);
void rgb_select_w(int state);
void mt_on_w(int state);
void sound_out_w(int state);
void printer_strb_w(int state);
void cas_out_w(int state);
void color_mode_w(uint8_t data);
void ramdac_w(offs_t offset, uint8_t data);
uint8_t gcw_r();
@ -124,6 +134,7 @@ private:
required_device<mc6845_device> m_crtc;
required_device<mb8876_device> m_fdc;
required_device_array<floppy_connector, 2> m_floppy;
required_device<ls259_device> m_ioctrl;
required_device<beep_device> m_beeper;
required_device<gfxdecode_device> m_gfxdecode;
required_device<palette_device> m_palette;
@ -142,7 +153,6 @@ private:
uint8_t m_display_reg = 0;
uint8_t m_fdc_irq_flag = 0;
uint8_t m_fdc_drq_flag = 0;
uint8_t m_system_data = 0;
struct { uint8_t r = 0, g = 0, b = 0; } m_pal;
uint8_t m_raminh = 0, m_raminh_pending_change = 0; //bankswitch
uint8_t m_raminh_prefetch = 0;
@ -574,29 +584,50 @@ uint8_t smc777_state::io_status_1d_r()
void smc777_state::io_control_w(uint8_t data)
{
/*
* flip-flop based
* ---x -111 cassette write
* ---x -110 printer strobe
* ---x -101 beeper
* ---x -100 cassette start (MONITOR_ON_OFF)
* ---x -011 0=RGB 1=Component
* ---x -010 0=525 lines 1=625 lines (NTSC/PAL switch?)
* ---x -001 1=display disable
* ---x -000 ram inibit signal
*/
m_system_data = data;
switch(m_system_data & 0x07)
{
case 0x00:
// "ROM / RAM register change is done at the beginning of the next M1 cycle"
m_raminh_pending_change = ((data & 0x10) >> 4) ^ 1;
m_raminh_prefetch = (uint8_t)(m_maincpu->state_int(Z80_R)) & 0x7f;
break;
case 0x02: printf("Screen line number %d\n",data & 0x10 ? 625 : 525); break;
case 0x05: m_beeper->set_state(data & 0x10); break;
default: printf("System FF W %02x\n",data); break;
}
m_ioctrl->write_bit(data & 0x07, BIT(data, 4));
}
void smc777_state::raminh_w(int state)
{
// "ROM / RAM register change is done at the beginning of the next M1 cycle"
m_raminh_pending_change = state ^ 1;
m_raminh_prefetch = (uint8_t)(m_maincpu->state_int(Z80_R)) & 0x7f;
}
void smc777_state::vsup_w(int state)
{
logerror("%s: Display %sabled\n", machine().describe_context(), state ? "dis" : "en");
}
void smc777_state::screen_lines_w(int state)
{
logerror("%s: Screen line number %d\n", machine().describe_context(), state ? 625 : 525);
}
void smc777_state::rgb_select_w(int state)
{
// 0=RGB 1=Component
logerror("%s: %s video selected\n", machine().describe_context(), state ? "Component" : "RGB");
}
void smc777_state::mt_on_w(int state)
{
logerror("%s: Cassette monitor %s\n", machine().describe_context(), state ? "on" : "off");
}
void smc777_state::sound_out_w(int state)
{
m_beeper->set_state(state);
}
void smc777_state::printer_strb_w(int state)
{
logerror("%s: Printer strobe %d\n", machine().describe_context(), !state);
}
void smc777_state::cas_out_w(int state)
{
logerror("%s: Cassette write %d\n", machine().describe_context(), state);
}
void smc777_state::color_mode_w(uint8_t data)
@ -664,11 +695,11 @@ uint8_t smc777_state::smc777_mem_r(offs_t offset)
uint8_t z80_r;
// TODO: do the bankswitch AFTER that the prefetch instruction is executed (hackish implementation)
if(m_raminh_prefetch != 0xff)
if(m_raminh_prefetch != 0xff && !machine().side_effects_disabled())
{
z80_r = (uint8_t)m_maincpu->state_int(Z80_R);
if(z80_r == ((m_raminh_prefetch+2) & 0x7f))
if(z80_r == ((m_raminh_prefetch+1) & 0x7f))
{
m_raminh = m_raminh_pending_change;
m_raminh_prefetch = 0xff;
@ -1112,6 +1143,16 @@ void smc777_state::smc777(machine_config &config)
I8041A(config, "mcu", 6_MHz_XTAL).set_disable();
LS259(config, m_ioctrl);
m_ioctrl->q_out_cb<0>().set(FUNC(smc777_state::raminh_w));
m_ioctrl->q_out_cb<1>().set(FUNC(smc777_state::vsup_w));
m_ioctrl->q_out_cb<2>().set(FUNC(smc777_state::screen_lines_w));
m_ioctrl->q_out_cb<3>().set(FUNC(smc777_state::rgb_select_w));
m_ioctrl->q_out_cb<4>().set(FUNC(smc777_state::mt_on_w));
m_ioctrl->q_out_cb<5>().set(FUNC(smc777_state::sound_out_w));
m_ioctrl->q_out_cb<6>().set(FUNC(smc777_state::printer_strb_w));
m_ioctrl->q_out_cb<7>().set(FUNC(smc777_state::cas_out_w));
/* video hardware */
SCREEN(config, m_screen, SCREEN_TYPE_RASTER);
m_screen->set_refresh_hz(60);