DEmul, the long‑dormant Dreamcast emulator, just lurched back to life and it brought one of Sega’s rarest arcade boards with it.
After seven years of public silence, longtime DEmul dev MetalliC dropped a new test build in the project’s Discord on December 11, focused almost entirely on Sega’s elusive Hikaru hardware. In the process, DEmul has become the only emulator currently capable of playing Planet Harriers with anything resembling the original arcade’s flair.
Hikaru is a strange one. It’s a souped‑up successor to the Naomi board, effectively a beefed‑up Dreamcast that powered only six arcade titles, things like Star Wars Racer Arcade and Planet Harriers, before Sega moved on. The boards are notoriously fragile thanks to a manufacturing flaw, which means that in 2026, working Hikarus are rare and getting rarer. Perfect candidate for preservation, terrible candidate for attracting a large pool of emulator devs.
DEmul actually added rough Hikaru support back in 2013, but when public builds stopped in 2018, hopes for meaningful progress basically froze in place. MetalliC never really stopped, though. Instead of poking at scarce, failing PCBs, he pivoted to deep code analysis: reverse‑engineering game binaries, leaning on Ghidra (after contributing SH‑4 fixes to make it usable), and even studying the Xbox 360 port of Virtual‑On Force, which helpfully wraps original code through OpenGL and Direct3D.
The result is a near‑rewrite of DEmul’s Hikaru 3D rendering. Lighting is now much closer to the real hardware, fog math has been corrected, the board’s unique “Z‑blend” transparency tricks finally show up properly in Planet Harriers’ first stage, motion blur is implemented, texture scrolling works (hello, moving lava), and the geometry engine passes the official Hikaru test ROM instead of spewing garbage. Even 2D overlays are in far better shape.
MetalliC still calls the emulation “not accurate” so much as “not too bad and close enough,” which is still huge progress. The current build is a test release meant to shake out major issues before a more official version that should add niceties like resolution switching and aspect ratio options for modern displays.
Whenever that lands, DEmul will effectively be the way to experience a tiny 1999–2001 slice of Sega’s arcade history without tracking down a failing Hikaru board and praying it survives shipping.
Source: Read Only Memo
