The Sharp x68000 Computer

A Wonderful 16-bit Japanese Computer System

The Sharp x68000 is the one computer system I wished I had the opportunity to own and I only discovered it via emulation and going through the retro computer listings on eBay and other sites. This is because the x68000 was only released in Japan and where I live, the most popular systems were the Commodore Amiga and to a lesser extent, the Atari ST, which also happened to be the machine I used the most at that time.

I have discovered many things about this machine through reading magazines, system manuals and a few Japanese websites/forums dedicated to this system. I have compiled some of the details about this system here and I will add to it as I discover new things.

I hope this becomes a useful article about this vastly unknown, yet wonderful system which was produced in Japan between 1987 and 1993.

Two Japanese Ads for the Sharp x68000


Sharp x68000 System Hardware Specification

Let’s start with some hardware specs for the standard X68000 ACE model which was released early 1998 (source: x68000 User Manual):

CPU

  • Motorola-Clone 68000 CPU (HD68HC000) 10Mhz made by Hitachi

ROM: Total 1Mb ROM

  • 128Kb BIOS
  • 768Kb Character Generator (16x16, 8x16, 8x8 — JIS 1+2)

RAM: Total 1Mb RAM

  • Maximum RAM is 4Mb
The majority of applications and games did not require more than 2Mb RAM and many were able to run on the standard 1Mb RAM. Street Fighter II is an exception which will not run with less than 4Mb RAM.

VRAM: Total 1Mb VRAM

  • 512Kb Text
  • 512Kb Graphic

Other RAM/VRAM

  • 32Kb Sprite VRAM
  • 16Kb Static RAM

Screen Resolutions

  • 256x240, 256x256
  • 512x240, 512x256, 512x512
  • 640x480
  • 768x512
  • 1024x1024

Screen Colors

  • 65,536 Total Color Palette
  • Max. 256 Simultaneous Colors on Screen

Sprites

  • 16x16 pixels
  • 128 sprites per screen; 16 sprites per line
  • 16 colors per sprite selected from 16 palettes

Graphics

  • Hardware scrolling
  • priority control
  • super-impose
  • 2 backgrounds

Sound — FM Synth

  • Yamaha YM2151 paired with a YM3012 DAC
  • 2 channels (stereo or 2 mono)
  • 8 voices, 8 octaves
  • Noise Generator
  • Sample Rate 22KHz

Sound — ADPCM

  • OKI MSM6258V
  • a 4 bit mono PCM

Expansion Slots

  • 2 slots available

Input/Output Ports

  • VGA Monitor Port — 15/24/31 kHz refresh rates
  • Component RGB In/Out — equipped for NTSC-J Cable TV
  • 2 x MSX Joypad Ports
  • Headphones Jack
  • Microphone Input

System Case and Input Devices

  • 2 x 5.25" floppy disk drives with soft eject
  • The tower case looks like two connected towers, with a retractable carrying handle
  • Software controlled power switch
  • QWERTY keyboard, 113 keys
  • Single Button Mouse

Hardware Variations Comparing Other Models

RAM

  • The Pro and other more later models had 12Mb RAM maximum

CPU

  • XVI Model (1991) — Genuine Motorola 68000 CPU 16MHz
  • X68030 Model (1993) — Genuine Motorola 68030 CPU 25MHz

Hard Drive — SASI Hard Disk Interface Maximum Storage Size

  • ACE-HD: 20MB
  • EXPERT-HD, PRO-HD, EXPERT II-HD, PRO II-HD: 40MB

Hard Drive — SCSI Hard Disk Interface Maximum Storage Size

  • SUPER-HD, XVI-HD, X68030-HD: 80MB

Expansion Slots

  • 4 slots available on Pro models

Sharp x68000 Power Supply Issues

One of the most common issues with x68000 systems today are issues with the power supply unit ‘blowing up’. This may have been contributed to by the fact that the power supply is in an ‘always on soft power state’ and there were no switches other than via the front of case power button that performed a timed power off. If you happen to get one of these machines, most likely they will be sold with a power supply issue. You will have to seek out a suitable replacement power supply or be prepared to ‘convert’ a suitable PC power supply for usage inside the x68000.

To convert a PC power supply you will need to get yourself an instruction manual with the power pin-outs for your model to make sure you are doing everything correctly plus you will need to use a 4.7k Ohm resistor, a suitable chip that performs an inverting role (because the power polarity is actually reversed) and be capable of doing some soldering. If you are not confident doing this, I suggest you seek out the services of someone with electronics repair skills as I take no responsibility offering this rough guide.

The power connections are no doubt different with each model — but this is a rough guide diagram for the ACE-HD model that I have researched the most.

For more in-depth details on fixing power supplies, these two links should be useful:


The Sharp x68000 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; 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; and others require hard disk installation.

Since the system’s OS Human68k, BIOS ROMs, console and SX-Window C compiler suites have been released as PUBLIC DOMAIN — all thanks to the @nifty Sharp Products Users’ Forum (FSHARP) — from April 1, 2000 with the consent of Sharp, Hudson, and other contributing companies, they are freely available for download. That forum is no longer available but what it all means is that x68000 system emulation is actually 100% legal! Note that some software/games on the system may still have copyright applicable.


Sharp x68000 Games

If you would like to read a story about games I have played on the X68000 and which ones are in my opinion I think are the best, feel free to read it here:


Sharp x68000 Game Box Art

Along with great games and near arcade perfect conversions, the x68000 also has in my opinion some of the best game cover art from the late 80’s and early 90’s. Many of the titles are hand drawn artworks and the amount of detail in these artworks is something else. Below are three examples of this fine artwork:

Detana!! TwinBee
Strider Hiryu
Fantastic Night Dreams: Cotton

Sharp x68000 Emulation

With the system’s power supply problems, this makes the computer unfortunately a reasonably difficult machine to maintain. However, with emulation of the x68000 virtually 100% accurate, you can experience this machine in all it’s glory using an emulator under Windows.

The emulator I usually recommend is WinX68k High-Speed v0.95. I know that finding a reliable version of this emulator can be difficult, I have decided to host WinX68k High Speed 0.95 with System Roms. As a bonus, I have included two games inside the same ZIP file — Flying Shark and Rygar — so you can quickly get going with x68000 emulation. I hope after reading this you have decided to give this wonderful Japanese release system a go, and it may have sparked your interest in other Japanese systems.

Links to more Sharp x68000 Information


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