PC Engine CD BIOS Progress: 8 DEV Entries, 0 Verified Compatible APIs
I'm working on oss-pce-cd-bios , an effort to build an open-source replacement for the PC Engine / TurboGrafx-CD System Card BIOS. My previous update focused on original HuC6280 routines and a synthetic CD-to-ADPCM DMA diagnostic. This update has a more visible milestone: The development ROM now has eight implemented entry points out of 81 candidates, up from just one in the previous post. That's…
The PC Engine / TurboGrafx-CD System Card BIOS open-source project has reached a milestone with eight implemented entry points out of 81 candidates. This represents genuine implementation progress, but it does not equate to eight compatible System Card services or guarantee that commercial CD games will boot. The current 256 KiB development-only image includes project-owned implementations at specific jump-table slots, while the remaining slots are nonreturning stubs.
The project is testing math and conversion routines within the development ROM's actual entry points and exercising them under a defined calling convention. However, these implementations are not claims of compatibility with the proprietary reference System Card ABI. The project tracks separate measurements for developer-defined entries, nonreturning stubs, and reference BIOS ABIs, none of which are currently verified.
The focus is on verifying caller-visible ABI contracts, establishing testable CD services, and eventually booting a disc through actual BIOS services before making broader compatibility claims.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
