Sharp X68000 Restoration: Build a Reliable 12 MB Japanese Retro Gaming PC
A Sharp X68000 cost 369,000 yen when it launched in 1987, equal to close to $7,000 in today's money. That price bought one of Japan's most powerful home computers, famous for arcade-quality game ports and its striking two-tower design.
This Sharp X68000 restoration began with a 2023 visit to BEEP in Akihabara. The system worked, but it needed cleaning, new capacitors, a safer power supply, modern storage, more memory, and better audio. After nearly three years, the machine became a fully upgraded 12 MB retro gaming computer.
Sharp X68000 Restoration Starts with Reliable Hardware
Cleaning a Dirty but Well-Preserved Computer
The computer was fully disassembled before any major upgrades began. Dust covered the case and internal parts, but the boards were in excellent shape, with no clear corrosion, broken traces, or major damage.
A careful teardown matters with hardware this old. Photograph cable positions, label screws, and inspect every board for liquid damage, cracked solder joints, corrosion, and damaged traces. Cleaning first also makes later faults easier to spot.
Replacing Nearly 40-Year-Old Capacitors
The original capacitors showed no obvious leaks or bulges, but visual checks cannot confirm that old capacitors still work correctly. Since the system was already apart, every capacitor was replaced with a Console5 kit.
The X68000 uses through-hole capacitors, making the process manageable. Each old part was desoldered and removed, then a replacement was installed with the correct polarity, soldered, and trimmed. Around 60 capacitors were replaced across the system boards.
Improving the Battery and Power Supply
The SRAM battery keeps system settings stored while the computer is off. Its purpose is similar to the battery in an original Game Boy cartridge, though the parts and circuits are different.
This X68000 Expert used a lithium battery, which is safer than the leak-prone rechargeable NiCad batteries found in some earlier models. A JST connector now links the board to a CR2032 holder mounted inside the case. Future battery changes require no full teardown or soldering.
The first power upgrade was a PicoPSU conversion. It worked, but a newer open-source Mattsoft replacement offered a better fit and used a high-quality Mean Well AC-to-DC supply. The finished unit stays inside the original case and improves long-term power reliability without changing the computer's appearance.
Adding Authentic MIDI Audio to the Sharp X68000
Recreating Rare Sharp MIDI Hardware
The MIDI card was the hardest modification in the project. X68000 community member TD Linux reverse engineered the rare original Sharp MIDI card and also designed an FPGA version. This build used the more authentic hardware design.
The board includes a Yamaha YM3802X MIDI controller chip, which was difficult to find. Recovered Gerber files provided the starting point, while cosmetic changes added a flat-black solder mask and gold accents. Community work like this keeps rare expansion hardware available to new owners.
Building and Testing the Meteori Card
The Meteori card was built with solder paste, a stencil, surface-mount parts, hot-air reflow, and through-hole components. The MIDI DIN connectors were too tall for the expansion bay, so their tops had to be trimmed for clearance. Optional 3.5 mm jacks were also installed before fitting the Yamaha chip.
HKR helped source parts and offered technical guidance during the build. Once complete, the card connected to a Roland SC-55 sound module and Roland speakers.
Akumajo Dracula, known outside Japan as Castlevania, confirmed that the card worked. The game detected the MIDI hardware on its first launch, and the SC-55 produced a much fuller soundtrack than the X68000's internal audio.
Expanding the X68000 to 12 MB of RAM
Building the Revised Gal's Panic Board
The system began with 2 MB of RAM. A community-designed Gal's Panic expansion board added another 10 MB, bringing the computer to its 12 MB maximum.
The original board came from stastsuk on the NFG forum. This build used a revised version by Arcade King from the Aussie Arcade forums. Its larger size makes installation and removal easier, while the updated design fixes issues found in the earlier version.
The RAM chips were installed with solder paste, then touched up by hand where needed. Through-hole parts followed, and the GAL chip was programmed with a JED file from GitHub. That file contains the logic needed to address the added memory.
Fixing the Jumpers and Testing Valis II
The first memory test failed. The system showed only about 3.3 MB instead of the expected 12 MB because several jumpers were left off. Those jumpers disable their related RAM chips, so all required positions had to be switched on.
After the correction, the computer reported about 11.5 MB of free memory. The small difference comes from memory used by the system and storage software. Valis II, which uses roughly 8 MB of RAM, loaded correctly and confirmed that the expansion worked.
Replacing X68000 Disk Limits with Solid-State Storage
Installing the SASI Converter and SD Adapter
The Hunk and Bonk Show SASI converter lets the X68000 use modern solid-state media as an internal hard-drive replacement. A CF adapter provides the storage interface for an SD card.
Installation involved mounting the converter to an adapter plate, replacing the original ribbon cable with an extended one, and securing the device near the power supply. Existing standoffs made for an optional internal hard drive provided clean mounting points. A small JST cable also connected the original hard-drive activity light.
One setup mistake caused a delay: the converter had not been connected to power. Checking every power lead should be an early troubleshooting step whenever a storage upgrade fails to boot.
Loading the 4 GB X68000 Software Image
The SD card received a 4 GB hard-drive image created by Hark, building on work by Shimetzu and other X68000 community members. It includes retail games, doujin releases, utilities, applications, media, and system tools in an organized menu.
The setup requires an X68000 master disk. After copying the image files to the SD card, the system settings were changed through the master disk using instructions from the community. Once configured, the computer booted straight into the hard-drive menu without repeated floppy swaps.
Retail releases appear on the D drive, while homebrew and doujin software sit on the E drive. Shooter folders divide games into horizontal and vertical categories, making the large collection easy to browse.
Turning the Restored Computer into a Complete Gaming System
Loading Cotton and Cho Ren Sha 68k
Cotton provided a test for the retail game library. After opening the D drive, the shooter folder, and the horizontal shooter category, the game launched with two presses of the Q key.
Cho Ren Sha 68k showed the homebrew side of the setup. Stored on the E drive, this popular vertical shooter is a strong example of the software preserved for the platform.
Using Controllers and Keeping the X68000 Character
A controller connects through the dedicated port on the front of the computer. Many games detect it and map the controls automatically, making the X68000 feel close to a high-end gaming console while keeping its computer roots.
The platform still has details found nowhere else. Cotton triggers a small keyboard light show during its intro, and the original hard-drive activity light flashes while the SD-based storage is accessed.
Protecting the Build with Custom Covers
The final upgrade was a set of handmade brown plaid wool covers for the two-tower computer and keyboard. They protect the system from dust and match its vintage style.
The tower cover includes a flap for the retractable handle and an opening with a Velcro flap for the permanently attached power cable. Lined interiors and finished hems give both covers a polished fit. Made by the creator's mother, they became the most personal part of the restoration.
What the Fully Upgraded Sharp X68000 Delivers
The finished system combines a full recap, modern internal power, an easy-to-replace CR2032 battery, 12 MB of RAM, MIDI audio, and SD-based SASI storage. Its original case and distinctive design remain intact.
The power supply and capacitor replacement form the reliability base. Solid-state storage brings the biggest daily improvement, while the MIDI card adds Roland SC-55 sound and the RAM board supports demanding software such as Valis II.
The project depended on community knowledge and shared hardware files. TD Linux, HKR, Arcade King, stastsuk, Derek/A-Team, Hark, Shimetzu, and Konji CRT each helped through reverse engineering, board design, parts sourcing, software preservation, setup advice, or hardware support.
Future X68000 owners should replace NiCad batteries quickly, inspect aging boards, recap old capacitors, confirm every jumper, program logic chips correctly, connect all power leads, and test upgrades with software that uses them.
Conclusion
This Sharp X68000 restoration turned a 369,000-yen Japanese computer from BEEP Akihabara into a reliable 12 MB gaming system. Nearly 40-year-old components were replaced, MIDI output was routed through a Roland SC-55, and an SD card replaced the limits of floppy-based storage.
The result keeps the character of the original machine while making it far easier to use today. Community-made hardware, preserved software, and careful repair show why the X68000 remains an active platform nearly four decades after its release.
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