X68000

X68000ACE-HD
Developer	Sharp Corporation
Release date	1987 (1987)
Operating system	Human68k, NetBSD, OS-9

The Sharp X68000, often referred to as the X68k, is a home computer released only in Japan by the Sharp Corporation. The first model was released in 1987, with a 10 MHz Motorola 68000 CPU (hence the name), 1 MB of RAM and no hard drive; the last model was released in 1993 with a 25 MHz Motorola 68030 CPU, 4 MB of RAM and optional 80 MB SCSI hard drive. RAM in these systems is expandable to 12 MB, though most games and applications did not require more than two.

Operating system

The X68k ran an operating system developed for Sharp by Hudson Soft, called Human68k, which features commands very similar to those in MS-DOS (typed in English). Pre-2.0 versions of the OS had command line output only for common utilities like "format" and "switch", while later versions included forms-based versions of these utilities, greatly improving their usability. At least three major versions of the OS were released, with several updates in between. Other operating systems available include NetBSD for X68030 and OS-9.

Early models had a GUI called "VS" (Visual Shell); later ones were packaged with SX-WINDOW. A third GUI called Ko-Windows existed; its interface is similar to Motif. These GUI shells could be booted from floppy disk or the system's hard drive. Most games also booted and ran from floppy disk; some were hard disk installable and others require hard disk installation.

Since the system's release, Human68k, console, and SX-Window C compiler suites and BIOS ROMs have been released as public domain and are freely available for download.

Case design

The X68000 features two soft-eject 5.25 in (133 mm) floppy drives, or in some of the compact models, two 3.5 in (89 mm) floppy drives, and a very distinct case design of two connected towers, divided by a retractable carrying handle. This system was also one of the first to feature a software-controlled power switch; pressing the switch would signal the system's software to save and shutdown, similar to the ATX design of modern PCs. The screen would fade to black and sound would fade to silence before the system turned off.

The system's keyboard has a mouse port built into either side. The front of the computer has a headphone jack, volume control, joystick, keyboard and mouse ports. The top has a retractable carrying handle (only on non-Compact models), a reset button, and a non-maskable interrupt (NMI) button. The rear has a variety of ports, including stereoscopic output for 3D goggles, FDD and HDD expansion ports, and I/O board expansion slots.

Display

The monitor supports 15/24 and 31 kHz with up to 65,535 colors and functions as a cable-ready television (NTSC-J standard) with composite video input. It was an excellent monitor for playing JAMMA compatible arcade boards due to its analog RGB input and standard-resolution refresh timing.

Disk I/O

Early machines use the rare Shugart Associates System Interface (SASI) for the hard disk interface; later versions adopted the industry-standard small computer system interface (SCSI). Per the hardware's capability, formatted SASI drives can be 10, 20 or 30 MB in size and can be logically partitioned as well. Floppy disks came in a couple of different formats, none of which are natively readable on other platforms, although software exists that can read and write these disks on a DOS or Windows 98 PC.

Expansion

Many add-on cards were released for the system, including networking (Neptune-X), SCSI, memory upgrades, CPU enhancements (JUPITER-X 68040/060 accelerator), and MIDI I/O boards. The system has two joystick ports, both 9-pin male and supporting Atari standard joysticks and MSX controllers. Capcom produced a converter that was originally sold packaged with the X68000 version of Street Fighter II′ that allowed users to plug in a Super Famicom or Mega Drive controller into the system. The adapter was made specifically so that users could plug in the Capcom Power Stick Fighter controller into the system.

Arcade at home

In terms of hardware, it was very similar to arcade machines of the time, and served as the Capcom CPS system development machine. It supported separate text RAM, graphic RAM and hardware sprites. Sound was produced internally via Yamaha's then top-of-the-line YM2151 FM synthesizer and a single channel OKI MSM6258V for PCM. Due to this and other similarities it played host to many arcade game ports in its day. Games made for this system included Parodius Da! －Shinwa kara Owarai e－, Ghouls 'n Ghosts, Strider, Final Fight, Alien Syndrome, Street Fighter II Dash, Akumajo Dracula (Castlevania in other regions, the X68000 version was ported to the PlayStation as Castlevania Chronicles), Cho Ren Sha 68k (which has a Windows port) and many others. Many games also supported the Roland SC-55 and MT-32 MIDI modules for sound as well as mixed-mode internal/external output.

List of X68000 series

Release Date	model name	model number	CPU	body		memory	Expansion I/O slot	FDD	HDD			Bundle software
				color	shape				SASI	SCSI	size
1987/03	X68000	CZ-600C	Hitachi HD68HC000 10 MHz (Motorola 68000 clone)	Gray/Black	Tower	1MB	2	5+1⁄4 x2	o	-	-	Human68k ver1.0 (OS) Gradius (Game)
1988/03	X68000 ACE	CZ-601C	Hitachi HD68HC000 10 MHz	Gray/Black	Tower	1MB	2	5+1⁄4 x2	o	-	-	Human68k ver1.01
	X68000 ACE-HD	CZ-611C									20MB
1989/03	X68000 EXPERT	CZ-602C	Hitachi HD68HC000 10 MHz	Gray/Black	Tower	2MB	2	5+1⁄4 x2	o	-	-	Human68k ver2.0
	X68000 EXPERT-HD	CZ-612C									40MB
	X68000 PRO	CZ-652C	Hitachi HD68HC000 10 MHz	Gray/Black	Horizontal	1MB	4	5+1⁄4 x2	o	-	-	Human68k ver2.0
	X68000 PRO-HD	CZ-662C									40MB
1990/03	X68000 EXPERT II	CZ-603C	Hitachi HD68HC000 10 MHz	Gray/Black	Tower	2MB	2	5+1⁄4 x2	o	-	-	Human68k ver2.0 SX-WINDOW ver2.0
	X68000 EXPERT II-HD	CZ-613C									40MB
1990/04	X68000 PRO II	CZ-653C	Hitachi HD68HC000 10 MHz	Gray/Black	Horizontal	1MB	4	5+1⁄4 x2	o	-	-	Human68k ver2.0 SX-Window ver2.0
	X68000 PRO II-HD	CZ-663C									40MB
1990/06	X68000 SUPER-HD	CZ-623C	Hitachi HD68HC000 10 MHz	Titan Black	Tower	2MB	2	5+1⁄4 x2	-	o	80MB	Human68k ver2.01 SX-Window ver2.0
1991/01	X68000 SUPER	CZ-604C									-
1991/05	X68000 XVI	CZ-634C	Motorola 68000 16 MHz	Titan Black	Tower	2MB	2	5+1⁄4 x2	-	o	-	Human68k ver2.02 SX-Window ver2.0
	X68000 XVI-HD	CZ-644C									80MB
1992/02	X68000 Compact	CZ-674C	Motorola 68000 16 MHz	Gray	mini Tower	2MB	2	3+1⁄2 x2	-	o	-	Human68k ver2.03 SX-Window ver2.0
1993/03	X68030	CZ-500	Motorola MC68EC030 25 MHz	Titan Black	Tower	4MB	2	5+1⁄4 x2	-	o	-	Human68k ver3.0 SX-Window ver3.0
	X68030-HD	CZ-510									80MB
1993/05	X68030 Compact	CZ-300	Motorola MC68EC030 25 MHz	Titan Black	mini Tower	4MB	2	3+1⁄2 x2	-	o	-	Human68k ver3.02 SX-Window ver3.0
	X68030 Compact-HD	CZ-310									80MB
(Cancelled)	Power X (provisional name)	CZ-xxxx	IBM PowerPC 601 66 MHz	Titan Black	Tower	8MB	2	unknown	-	o	240MB	SX-Window ver4.0

List of X68000 games

Main article: List of Sharp X68000 games

Technical specifications

• CPU / Clock speed:

X68000 models: Motorola 68000 / 10 MHz

XVI models: Motorola 68000 / 16 MHz

X68030 models: Motorola 68030 / 25 MHz

• ROM: 1 MiB (128KB BIOS,768KB Character Generator)
• RAM: 1-4 MiB (Expandable up to 12 MB)
• VRAM: 512 KiB graphic + 512 KiB text + 32 KiB sprite VRAM
• SRAM: 16 KiB Static RAM
• Screen resolutions:

256 x 240

256 x 256

512 x 240

512 x 256

512 x 512

640 x 480

768 x 512

1024 x 1024

• Maximum colors on screen: 65536

• Sprite count: 128 sprites, 32 sprites per scanline
• Sprite size: 16 x 16
• Sprite colors: 16 colors per palette, selectable from 16 palettes

• BG plane resolutions: 256 x 256 or 512 x 512
• BG chip size: 8 x 8 or 16 x 16

• Graphics hardware: Hardware scrolling, priority control, super-impose
• Sound chips:

Yamaha YM2151 (eight FM stereo channels)

OKI MSM6258v (one 4 bit ADPCM mono channel)

• Expansion: 2 card slots (4 on Pro models)

• I/O Ports:

2 MSX compatible joystick ports

Audio IN / OUT

Stereo scope/3D goggles port

TV/monitor Control

RGB/NTSC Video Image I/O

Expansion (2 slots)

External FDD (up to 2)

SASI/SCSI (depending on model)

RS232 serial port

Parallel port

Headphone and microphone ports

• Floppy Drives:

Two soft-eject 5.25″ floppy drives, 1.2 MB each

Two 3.5″ floppy drives, 1.44 MB each (compact models)

• Hard Disk: 20-80 MB SASI/SCSI (depending on model)
• Operating Systems: Human68k (MS DOS-alike developed by Hudson), SX-Windows GUI
• Power Input: AC 100v, 50/60Hz
• Weight: ~8 kg (~10 kg Pro)

See also

• X68000's MDX
• Sharp X1, the predecessor of the X68000

External links

• Website about the actual hardware
• Japanese Computer Emulation Centre
• Japanese site for official public domain software and ROMs
• English site with X68000 Hardware information and emulators
• X68000 review at old-computers.com