isbc8024: new multibus card with unknown firmware [Andy Welburn]

scripts/src/bus.lua

@@ -4667,6 +4667,8 @@ if (BUSES["MULTIBUS"]~=null) then
 		MAME_DIR .. "src/devices/bus/multibus/multibus.h",
 		MAME_DIR .. "src/devices/bus/multibus/isbc202.cpp",
 		MAME_DIR .. "src/devices/bus/multibus/isbc202.h",
+		MAME_DIR .. "src/devices/bus/multibus/isbc8024.cpp",
+		MAME_DIR .. "src/devices/bus/multibus/isbc8024.h",
 		MAME_DIR .. "src/devices/bus/multibus/cpuap.cpp",
 		MAME_DIR .. "src/devices/bus/multibus/cpuap.h",
 		MAME_DIR .. "src/devices/bus/multibus/serad.cpp",

src/devices/bus/multibus/isbc8024.cpp

@@ -0,0 +1,156 @@
+// license:BSD-3-Clause
+// copyright-holders:Patrick Mackinlay
+
+/*
+ * Intel iSBC 80/24 Single Board Computer
+ *
+ * Sources:
+ *  - http://www.bitsavers.org/pdf/intel/iSBC/148437-001_iSBC_80_24A_Hardware_Reference_Manual_Nov85.pdf
+ *
+ * TODO:
+ *  - configurable eprom quantity/size
+ *  - configurable irq, clock and I/O
+ *  - reverse engineer unknown firmware
+ *  - led output
+ */
+
+#include "emu.h"
+#include "isbc8024.h"
+
+#define VERBOSE 0
+#include "logmacro.h"
+
+DEFINE_DEVICE_TYPE(ISBC8024, isbc8024_device, "isbc8024", "Intel iSBC 80/24 Single Board Computer")
+
+isbc8024_device::isbc8024_device(machine_config const &mconfig, char const *tag, device_t *owner, u32 clock)
+	: device_t(mconfig, ISBC8024, tag, owner, clock)
+	, device_multibus_interface(mconfig, *this)
+	, m_cpu(*this, "cpu")
+	, m_pit(*this, "pit")
+	, m_pci(*this, "pci")
+	, m_ppi(*this, "ppi%u", 0U)
+	, m_pic(*this, "pic")
+	, m_j3(*this, "j3")
+	, m_conf(*this, "CONF")
+	, m_installed(false)
+{
+}
+
+ROM_START(isbc8024)
+	ROM_REGION(0x1000, "eprom", 0)
+	ROM_SYSTEM_BIOS(0, "unknown", "unknown")
+	ROMX_LOAD("unknown.u50", 0x000, 0x800, CRC(28b18721) SHA1(37526ed0a4f1e910fc0a8f6af0708c77a7358f69), ROM_BIOS(0))
+	ROMX_LOAD("unknown.u51", 0x800, 0x800, CRC(9e49f6ad) SHA1(565ab4740d3151eb4d8ef9ff3e02570cf7804be1), ROM_BIOS(0))
+ROM_END
+
+static INPUT_PORTS_START(isbc8024)
+	PORT_START("CONF")
+	PORT_CONFNAME(0x0003, 0x0003, "Size")
+	PORT_CONFSETTING(     0x0000, "None")
+	PORT_CONFSETTING(     0x0001, "2048")
+	PORT_CONFSETTING(     0x0002, "4096")
+	PORT_CONFSETTING(     0x0003, "8192")
+
+	PORT_CONFNAME(0xf000, 0xf000, "End")
+	PORT_CONFSETTING(     0x3000, "3FFF")
+	PORT_CONFSETTING(     0x7000, "7FFF")
+	PORT_CONFSETTING(     0xb000, "BFFF")
+	PORT_CONFSETTING(     0xf000, "FFFF")
+INPUT_PORTS_END
+
+const tiny_rom_entry *isbc8024_device::device_rom_region() const
+{
+	return ROM_NAME(isbc8024);
+}
+
+ioport_constructor isbc8024_device::device_input_ports() const
+{
+	return INPUT_PORTS_NAME(isbc8024);
+}
+
+void isbc8024_device::device_start()
+{
+}
+
+void isbc8024_device::device_reset()
+{
+	if (!m_installed)
+	{
+		ioport_value const conf = m_conf->read();
+		if (conf & 3)
+		{
+			size_t const ram_size = 1024 << (conf & 3);
+			offs_t ram_end = (conf & 0xf000) | 0x0fff;
+
+			std::unique_ptr<u8[]> const ram = std::make_unique<u8[]>(ram_size);
+			m_cpu->space(AS_PROGRAM).install_ram(ram_end - ram_size + 1, ram_end, ram.get());
+		}
+
+		// TODO: what's exposed to the Multibus?
+		m_bus->int_callback<2>().set(m_pic, FUNC(pic8259_device::ir1_w));
+
+		m_installed = true;
+	}
+}
+
+void isbc8024_device::device_add_mconfig(machine_config &config)
+{
+	I8085A(config, m_cpu, 19'354'000 / 2);
+	m_cpu->set_addrmap(AS_PROGRAM, &isbc8024_device::cpu_mem_map);
+	m_cpu->set_addrmap(AS_IO, &isbc8024_device::cpu_pio_map);
+
+	PIT8254(config, m_pit);
+	m_pit->set_clk<0>(19'354'000 / 18);
+	m_pit->set_clk<1>(19'354'000 / 18);
+	m_pit->set_clk<2>(19'354'000 / 18);
+	m_pit->out_handler<0>().set(m_pic, FUNC(pic8259_device::ir2_w));
+	//m_pit->out_handler<1>().set(m_pic, FUNC(pic8259_device::ir?));
+	m_pit->out_handler<2>().append(m_pci, FUNC(i8251_device::write_rxc));
+	m_pit->out_handler<2>().append(m_pci, FUNC(i8251_device::write_txc));
+
+	I8251(config, m_pci, 0);
+
+	I8255(config, m_ppi[0], 0); // j1
+	I8255(config, m_ppi[1], 0); // j2
+
+	PIC8259(config, m_pic);
+	m_pic->out_int_callback().set_inputline(m_cpu, I8085_INTR_LINE);
+
+	RS232_PORT(config, m_j3, default_rs232_devices, nullptr);
+
+	m_pci->txd_handler().set(m_j3, FUNC(rs232_port_device::write_txd));
+	m_pci->dtr_handler().set(m_j3, FUNC(rs232_port_device::write_dtr));
+	m_pci->rts_handler().set(m_j3, FUNC(rs232_port_device::write_rts));
+	m_j3->rxd_handler().set(m_pci, FUNC(i8251_device::write_rxd));
+	m_j3->dsr_handler().set(m_pci, FUNC(i8251_device::write_dsr));
+	m_j3->cts_handler().set(m_pci, FUNC(i8251_device::write_cts));
+}
+
+void isbc8024_device::cpu_mem_map(address_map &map)
+{
+	// default off-board mem access to multibus
+	map(0x0000, 0xffff).rw(FUNC(isbc8024_device::bus_mem_r), FUNC(isbc8024_device::bus_mem_w));
+
+	// TODO: variable number and size of EPROMs
+	map(0x0000, 0x0fff).rom().region("eprom", 0);
+}
+
+void isbc8024_device::cpu_pio_map(address_map &map)
+{
+	// default off-board pio access to multibus
+	map(0x00, 0xff).rw(FUNC(isbc8024_device::bus_pio_r), FUNC(isbc8024_device::bus_pio_w));
+
+	map(0xd4, 0xd4).noprw(); // TODO: power fail
+	//map(0xd5, 0xd5); // system bus override
+	map(0xd6, 0xd6).lw8([this](u8 data) { popmessage("LED"); }, "led_w"); // led diagnostic indicator
+	map(0xd7, 0xd7).noprw(); // reserved
+	map(0xd8, 0xd9).rw(m_pic, FUNC(pic8259_device::read), FUNC(pic8259_device::write)).mirror(0x02);
+	map(0xdc, 0xdf).rw(m_pit, FUNC(pit8254_device::read), FUNC(pit8254_device::write));
+	map(0xe4, 0xe7).rw(m_ppi[0], FUNC(i8255_device::read), FUNC(i8255_device::write));
+	map(0xe8, 0xeb).rw(m_ppi[1], FUNC(i8255_device::read), FUNC(i8255_device::write));
+	map(0xec, 0xed).rw(m_pci, FUNC(i8251_device::read), FUNC(i8251_device::write)).mirror(0x02);
+	//map(0xc0, 0xc7); // mutimodule 1 mcs0/ j5
+	//map(0xc8, 0xcf); // mutimodule 1 mcs1/ j5
+	//map(0xf0, 0xf7); // mutimodule 2 mcs0/ j6
+	//map(0xf8, 0xff); // mutimodule 2 mcs1/ j6
+}

src/devices/bus/multibus/isbc8024.h

@@ -0,0 +1,57 @@
+// license:BSD-3-Clause
+// copyright-holders:Patrick Mackinlay
+
+#ifndef MAME_BUS_MULTIBUS_ISBC8024_H
+#define MAME_BUS_MULTIBUS_ISBC8024_H
+
+#pragma once
+
+#include "multibus.h"
+
+#include "cpu/i8085/i8085.h"
+#include "machine/pit8253.h"
+#include "machine/i8251.h"
+#include "machine/i8255.h"
+#include "machine/pic8259.h"
+
+#include "bus/rs232/rs232.h"
+
+class isbc8024_device
+	: public device_t
+	, public device_multibus_interface
+{
+public:
+	isbc8024_device(machine_config const &mconfig, char const *tag, device_t *owner, u32 clock);
+
+protected:
+	// device_t overrides
+	virtual const tiny_rom_entry *device_rom_region() const override;
+	virtual void device_add_mconfig(machine_config &config) override;
+	virtual ioport_constructor device_input_ports() const override;
+	virtual void device_start() override;
+	virtual void device_reset() override;
+
+private:
+	void cpu_mem_map(address_map &map);
+	void cpu_pio_map(address_map &map);
+
+	void bus_mem_w(offs_t offset, u8 data) { m_bus->space(AS_PROGRAM).write_byte(offset, data); }
+	u8 bus_mem_r(offs_t offset) { return m_bus->space(AS_PROGRAM).read_byte(offset); }
+	void bus_pio_w(offs_t offset, u8 data) { m_bus->space(AS_IO).write_byte(offset, data); }
+	u8 bus_pio_r(offs_t offset) { return m_bus->space(AS_IO).read_byte(offset); }
+
+	required_device<i8085a_cpu_device> m_cpu;
+	required_device<pit8254_device> m_pit;
+	required_device<i8251_device> m_pci;
+	required_device_array<i8255_device, 2> m_ppi;
+	required_device<pic8259_device> m_pic;
+	required_device<rs232_port_device> m_j3;
+
+	required_ioport m_conf;
+
+	bool m_installed;
+};
+
+DECLARE_DEVICE_TYPE(ISBC8024, isbc8024_device)
+
+#endif // MAME_BUS_MULTIBUS_ISBC8024_H