apple2: start reverse-engineering the AE PC Transporter card [R. Belmont]

scripts/src/bus.lua

@@ -1445,6 +1445,8 @@ if (BUSES["A2BUS"]~=null) then
 		MAME_DIR .. "src/devices/bus/a2bus/ramcard128k.h",
 		MAME_DIR .. "src/devices/bus/a2bus/ezcgi.cpp",
 		MAME_DIR .. "src/devices/bus/a2bus/ezcgi.h",
+		MAME_DIR .. "src/devices/bus/a2bus/pc_xporter.cpp",
+		MAME_DIR .. "src/devices/bus/a2bus/pc_xporter.h",
 	}
 end
 

src/devices/bus/a2bus/pc_xporter.cpp

@@ -0,0 +1,255 @@
+// license:BSD-3-Clause
+// copyright-holders:R. Belmont
+/*********************************************************************
+
+    pcxporter.cpp
+
+    Implementation of the Applied Engineering PC Transporter card
+	Preliminary version by R. Belmont
+
+    The PC Transporter is basically a PC-XT on an Apple II card.
+    Features include:
+    - V30 CPU @ 4.77 MHz
+    - 768K of RAM, which defines the V30 address space from 0x00000 to 0xBFFFF
+      and is fully read/writable by the Apple's CPU.
+    - Usual XT hardware, mostly inside custom ASICs.  There's a discrete
+      NEC uPD71054 (i8254-compatible PIT) though.
+    - CGA-compatible video, output to a separate CGA monitor or NTSC-compliant analog
+      RGB monitor (e.g. the IIgs RGB monitor).
+    - XT-compatible keyboard interface.
+    - PC-style floppy controller: supports 360K 5.25" disks and 720K 3.5" disks
+    - HDD controller which is redirected to a file on the Apple's filesystem
+
+    The V30 BIOS is downloaded by the Apple; the Apple also writes text to the CGA screen prior to 
+    the V30's being launched.
+
+    The board was developed by The Engineering Department, a company made up mostly of early Apple 
+    engineers including Apple /// designer Dr. Wendall Sander and ProDOS creator Dick Huston.
+
+    Software and user documentation at: 
+    http://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Interface%20Cards/CPU/AE%20PC%20Transporter/
+
+    Notes:
+    	Registers live at CFxx; access CFFF to clear C800 reservation,
+    	then read Cn00 to map C800-CFFF first.
+ 
+        PC RAM from 0xA0000-0xAFFFF is where the V30 BIOS is downloaded,
+        plus used for general storage by the system.
+        RAM from 0xB0000-0xBFFFF is the CGA framebuffer as usual.
+
+    	CF00: PC memory pointer (bits 0-7)
+    	CF01: PC memory pointer (bits 8-15)
+    	CF02: PC memory pointer (bits 16-23)
+    	CF03: read/write PC memory at the pointer and increment the pointer
+    	CF04: read/write PC memory at the pointer and *don't* increment the pointer
+ 
+    TODO:
+        - A2 probably also can access the V30's I/O space: where's that at?  CF0E/CF0F
+          are suspects...
+        - There's likely A2 ROM at CnXX and C800-CBFF to support the "Slinky" memory
+          expansion card emulation function inside one of the custom ASICs.  Need to
+          dump this...
+
+*********************************************************************/
+
+#include "pc_xporter.h"
+
+/***************************************************************************
+    PARAMETERS
+***************************************************************************/
+
+//**************************************************************************
+//  GLOBAL VARIABLES
+//**************************************************************************
+
+const device_type A2BUS_PCXPORTER = &device_creator<a2bus_pcxporter_device>;
+
+static MACHINE_CONFIG_FRAGMENT( pcxporter )
+MACHINE_CONFIG_END
+
+/***************************************************************************
+    FUNCTION PROTOTYPES
+***************************************************************************/
+
+//-------------------------------------------------
+//  machine_config_additions - device-specific
+//  machine configurations
+//-------------------------------------------------
+
+machine_config_constructor a2bus_pcxporter_device::device_mconfig_additions() const
+{
+	return MACHINE_CONFIG_NAME( pcxporter );
+}
+
+//**************************************************************************
+//  LIVE DEVICE
+//**************************************************************************
+
+a2bus_pcxporter_device::a2bus_pcxporter_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source) :
+	device_t(mconfig, type, name, tag, owner, clock, shortname, source),
+	device_a2bus_card_interface(mconfig, *this)
+{
+}
+
+a2bus_pcxporter_device::a2bus_pcxporter_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
+	device_t(mconfig, A2BUS_PCXPORTER, "Applied Engineering PC Transporter", tag, owner, clock, "a2pcxport", __FILE__),
+	device_a2bus_card_interface(mconfig, *this)
+{
+}
+
+//-------------------------------------------------
+//  device_start - device-specific startup
+//-------------------------------------------------
+
+void a2bus_pcxporter_device::device_start()
+{
+	// set_a2bus_device makes m_slot valid
+	set_a2bus_device();
+
+	memset(m_ram, 0, 768*1024);
+	memset(m_regs, 0, 0x400);
+	m_offset = 0;
+
+	save_item(NAME(m_ram));
+	save_item(NAME(m_regs));
+	save_item(NAME(m_offset));
+}
+
+void a2bus_pcxporter_device::device_reset()
+{
+}
+
+
+/*-------------------------------------------------
+    read_c0nx - called for reads from this card's c0nx space
+-------------------------------------------------*/
+
+UINT8 a2bus_pcxporter_device::read_c0nx(address_space &space, UINT8 offset)
+{
+	switch (offset)
+	{
+		default:
+			printf("Read c0n%x (PC=%x)\n", offset, space.device().safe_pc());
+			break;
+	}
+
+	return 0xff;
+}
+
+
+/*-------------------------------------------------
+    write_c0nx - called for writes to this card's c0nx space
+-------------------------------------------------*/
+
+void a2bus_pcxporter_device::write_c0nx(address_space &space, UINT8 offset, UINT8 data)
+{
+	switch (offset)
+	{
+		default:
+			printf("Write %02x to c0n%x (PC=%x)\n", data, offset, space.device().safe_pc());
+			break;
+	}
+}
+
+/*-------------------------------------------------
+    read_cnxx - called for reads from this card's cnxx space
+-------------------------------------------------*/
+
+UINT8 a2bus_pcxporter_device::read_cnxx(address_space &space, UINT8 offset)
+{
+	// read only to trigger C800?
+	return 0xff;
+}
+
+void a2bus_pcxporter_device::write_cnxx(address_space &space, UINT8 offset, UINT8 data)
+{
+	printf("Write %02x to cn%02x (PC=%x)\n", data, offset, space.device().safe_pc());
+}
+
+/*-------------------------------------------------
+    read_c800 - called for reads from this card's c800 space
+-------------------------------------------------*/
+
+UINT8 a2bus_pcxporter_device::read_c800(address_space &space, UINT16 offset)
+{
+//	printf("Read C800 at %x\n", offset + 0xc800);
+
+	if (offset < 0x400)
+	{
+		return 0xff;
+	}
+	else
+	{
+		UINT8 rv;
+
+		switch (offset)
+		{
+			case 0x700:
+				return m_offset & 0xff;
+
+			case 0x701:
+				return (m_offset >> 8) & 0xff;
+
+			case 0x702:
+				return (m_offset >> 16) & 0xff;
+
+			case 0x703:	// read with increment
+				rv = m_ram[m_offset];
+				m_offset++;
+				return rv;
+
+			case 0x704:	// read w/o increment
+				rv = m_ram[m_offset];
+				return rv;
+		}
+
+		return m_regs[offset];
+	}
+}
+
+/*-------------------------------------------------
+    write_c800 - called for writes to this card's c800 space
+-------------------------------------------------*/
+void a2bus_pcxporter_device::write_c800(address_space &space, UINT16 offset, UINT8 data)
+{
+	if (offset < 0x400)
+	{
+	}
+	else
+	{
+		switch (offset)
+		{
+			case 0x700:
+				m_offset &= ~0xff;
+				m_offset |= data;
+//				printf("offset now %x (PC=%x)\n", m_offset, space.device().safe_pc());
+				break;
+
+			case 0x701:
+				m_offset &= ~0xff00;
+				m_offset |= (data<<8);
+//				printf("offset now %x (PC=%x)\n", m_offset, space.device().safe_pc());
+				break;
+
+			case 0x702:
+				m_offset &= ~0xff0000;
+				m_offset |= (data<<16);
+//				printf("offset now %x (PC=%x)\n", m_offset, space.device().safe_pc());
+				break;
+
+			case 0x703:	// write w/increment
+				m_ram[m_offset] = data;
+				m_offset++;
+				break;
+
+			case 0x704:	// write w/o increment
+				m_ram[m_offset] = data;
+				break;
+
+			default:
+				printf("%02x to C800 at %x\n", data, offset + 0xc800);
+				m_regs[offset] = data;
+				break;
+		}
+	}
+}

src/devices/bus/a2bus/pc_xporter.h

@@ -0,0 +1,53 @@
+// license:BSD-3-Clause
+// copyright-holders:R. Belmont
+/*********************************************************************
+
+    pc_xporter.h
+
+    Implementation of the Applied Engineering PC Transporter card
+
+*********************************************************************/
+
+#pragma once
+
+#include "emu.h"
+#include "a2bus.h"
+#include "machine/genpc.h"
+
+//**************************************************************************
+//  TYPE DEFINITIONS
+//**************************************************************************
+
+class a2bus_pcxporter_device:
+	public device_t,
+	public device_a2bus_card_interface
+{
+public:
+	// construction/destruction
+	a2bus_pcxporter_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source);
+	a2bus_pcxporter_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+
+	// optional information overrides
+	virtual machine_config_constructor device_mconfig_additions() const override;
+
+protected:
+	virtual void device_start() override;
+	virtual void device_reset() override;
+
+	// overrides of standard a2bus slot functions
+	virtual UINT8 read_c0nx(address_space &space, UINT8 offset) override;
+	virtual void write_c0nx(address_space &space, UINT8 offset, UINT8 data) override;
+	virtual UINT8 read_cnxx(address_space &space, UINT8 offset) override;
+	virtual void write_cnxx(address_space &space, UINT8 offset, UINT8 data) override;
+	virtual UINT8 read_c800(address_space &space, UINT16 offset) override;
+	virtual void write_c800(address_space &space, UINT16 offset, UINT8 data) override;
+
+private:
+	UINT8 m_ram[768*1024];
+	UINT8 m_regs[0x400];
+	UINT32 m_offset;
+};
+
+// device type definition
+extern const device_type A2BUS_PCXPORTER;
+

src/mame/drivers/apple2e.cpp

@@ -144,6 +144,7 @@ Address bus A0-A11 is Y0-Y11
 #include "bus/a2bus/timemasterho.h"
 #include "bus/a2bus/mouse.h"
 #include "bus/a2bus/ezcgi.h"
+#include "bus/a2bus/pc_xporter.h"
 #include "bus/a2bus/a2eauxslot.h"
 #include "bus/a2bus/a2estd80col.h"
 #include "bus/a2bus/a2eext80col.h"
@@ -3188,6 +3189,7 @@ static SLOT_INTERFACE_START(apple2_cards)
 	SLOT_INTERFACE("ezcgi9938", A2BUS_EZCGI_9938)   /* E-Z Color Graphics Interface (TMS9938) */
 	SLOT_INTERFACE("ezcgi9958", A2BUS_EZCGI_9958)   /* E-Z Color Graphics Interface (TMS9958) */
 //  SLOT_INTERFACE("magicmusician", A2BUS_MAGICMUSICIAN)    /* Magic Musician Card */
+	SLOT_INTERFACE("pcxport", A2BUS_PCXPORTER) /* Applied Engineering PC Transporter */
 SLOT_INTERFACE_END
 
 static SLOT_INTERFACE_START(apple2eaux_cards)