Sharp X68000

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Sharp X68000

X68000ACE-HD

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, 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 didn't 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" floppy drives, or in some of the compact models, two 3.5" 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, although rather poorly designed overall, 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 plethora 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 megabytes in size and can be logically partitoned 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. MSX controllers work natively and Mega Drive/Genesis controllers can be used in conjunction with the adapter that came with Super Street Fighter 2.

Arcade at home

Hardware-wise, it's very similar to arcade hardware of the time (It was Capcom CPS system development machine) It supports separate text RAM, graphic RAM and hardware sprites. Sound is 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 includes Parodius Da! －Shinwa kara Owarai e－, Final Fight, Street Fighter II Dash, Ghosts 'n Goblins, 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 supports the Roland SC-55 and MT-32 MIDI modules for sound as well as mixed-mode internal/external output.

List of X68000 series

Technical Specifications

• CPU / Clock speed:

Motorola 68000 / 10 MHz (X68000 models).

Motorola 68000 / 16 MHz (XVI models).

Motorola 68030 / 25 MHz (X68030 models).

• ROM:1 MB(128KB BIOS,768KB Character Generator)
• RAM: 1-4 MB (Expandable up to 12 MB)
• VRAM: 512 KB graphic + 512 KB text + 32KB Sprite VRAM
• SRAM: 16KB 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 colours on screen:

512 x 512: 65536 non-indexed colors on screen, or 256 indexed colors with 65536 palette and 128 sprites.

1024 x 1024: 16 indexed colors ,65536 palette.

• Sprites number:128 sprites, 32 sprites per scanline
• Sprite Size: 16 x 16
• Sprite colors: 16 colors per sprite/palette ,selectable from 16 palettes

256 total colors for the whole 128 sprites

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

Yamaha YM2151 (eight FM stereo channels)

OKI MSM6258 (one 4 bit PCM 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, 1.2MB each two 3.5 floppy drives, 1.4MB each (compact models)

• Hard Disk: 20-80MB 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

External links

• Website about the actual hardware
• Technical Data & description of X68000
• 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