fidelity/csc: improve irq active duration

src/mame/fidelity/csc.cpp

@@ -13,9 +13,7 @@ TODO:
 - do ca1_w/cb1_w better, it's annoying since it's going through sensorboard_device
   (it works fine though, since PIA interrupts are not connected)
 - hook up csce I/O properly, it doesn't have PIAs
-- verify csc/super9cc irq duration, it was measured 73.425us but that's too long,
-  so it's using the one from csce for now instead
-- is super9cc 101-1024B03 really 2KB? rom chip looks the same as the other ones
+- verify super9cc maskrom dump
 
 *******************************************************************************
 
@@ -619,12 +617,12 @@ INPUT_PORTS_END
 
 void csc_state::csc(machine_config &config)
 {
-	/* basic machine hardware */
+	// basic machine hardware
 	M6502(config, m_maincpu, 3.9_MHz_XTAL/2); // from 3.9MHz resonator
 	m_maincpu->set_addrmap(AS_PROGRAM, &csc_state::csc_map);
 
 	auto &irq_clock(CLOCK(config, "irq_clock", 38.4_kHz_XTAL/64)); // through 4060 IC, 600Hz
-	irq_clock.set_pulse_width(attotime::from_nsec(10480)); // 74LS221 (4.7K, 5nF), measured ~10.48us
+	irq_clock.set_pulse_width(attotime::from_nsec(42750)); // measured ~42.75us
 	irq_clock.signal_handler().set_inputline(m_maincpu, M6502_IRQ_LINE);
 
 	PIA6821(config, m_pia[0], 0);
@@ -644,12 +642,12 @@ void csc_state::csc(machine_config &config)
 	m_board->init_cb().set(m_board, FUNC(sensorboard_device::preset_chess));
 	m_board->set_delay(attotime::from_msec(200));
 
-	/* video hardware */
+	// video hardware
 	PWM_DISPLAY(config, m_display).set_size(9, 16);
 	m_display->set_segmask(0xf, 0x7f);
 	config.set_default_layout(layout_fidel_csc);
 
-	/* sound hardware */
+	// sound hardware
 	SPEAKER(config, "speaker").front_center();
 	S14001A(config, m_speech, 25000); // R/C circuit, around 25khz
 	m_speech->ext_read().set(FUNC(csc_state::speech_r));
@@ -662,30 +660,28 @@ void csc_state::csce(machine_config &config)
 {
 	csc(config);
 
-	/* basic machine hardware */
 	m_maincpu->set_clock(4_MHz_XTAL);
 	m_maincpu->set_addrmap(AS_PROGRAM, &csc_state::csce_map);
+
+	// shorter irq, 74LS221 (4.7K, 5nF), measured ~10.48us
+	subdevice<clock_device>("irq_clock")->set_pulse_width(attotime::from_nsec(10480));
 }
 
 void csc_state::cscet(machine_config &config)
 {
 	csce(config);
-
-	/* basic machine hardware */
 	m_maincpu->set_clock(5_MHz_XTAL);
 }
 
 void su9_state::su9(machine_config &config)
 {
 	csc(config);
-
-	/* basic machine hardware */
 	config.set_default_layout(layout_fidel_su9);
 }
 
 void csc_state::rsc(machine_config &config)
 {
-	/* basic machine hardware */
+	// basic machine hardware
 	M6502(config, m_maincpu, 1800000); // measured approx 1.81MHz
 	m_maincpu->set_addrmap(AS_PROGRAM, &csc_state::rsc_map);
 
@@ -704,11 +700,11 @@ void csc_state::rsc(machine_config &config)
 	m_board->set_spawnpoints(2);
 	m_board->set_delay(attotime::from_msec(300));
 
-	/* video hardware */
+	// video hardware
 	PWM_DISPLAY(config, m_display).set_size(9, 16);
 	config.set_default_layout(layout_fidel_rsc);
 
-	/* sound hardware */
+	// sound hardware
 	SPEAKER(config, "speaker").front_center();
 	DAC_1BIT(config, m_dac).add_route(ALL_OUTPUTS, "speaker", 0.25);
 }

src/mame/tecmo/senjyo.cpp

@@ -14,6 +14,7 @@ TODO:
 - remove memory pointers for video attribute RAM area (r/w handlers instead?),
   then the workaround at the end of starforb_map isn't needed, and m_scrollhack
   can probably be removed too
+- lowpass filter on DAC?
 
 Note:
 - Star Force shows default MAME palette at POST. Flipped to all_black for now.

src/mame/universal/redclash.cpp

@@ -15,7 +15,7 @@ Notes:
 TODO:
 - Colors are not right. In zerohour P1 score should be white, the top score green,
   and "TOP" should be magenta. How is this determined? It's as if only the top part
-  of the screen has this exception. Sprite colors look ok.
+  of the screen has this exception. Maybe via the unknown PROM? Sprite colors look ok.
 - Some graphical problems in both games
 - redclash supports more background layer effects: white+mixed with other colors,
   used in canyon parts and during the big ufo explosion