PC-98 Compatibility Patches

Small fixes for original media

Keep the game. Patch the obstacle.

A home for compact PC-98 compatibility patches, with exact input hashes and clear instructions. Bring your own original game media.

Patch files only. This page does not provide game executables, floppy images, CD images, manuals, or DOS system files.

Release 01

Black Thorne · PC-98

Bypasses the manual page/line/character question in SETBT.COM during installation. Each IPS changes three bytes on Disk 1. The game executables and Disk 2 are unchanged.

PC-9801

16-color version

Apply to the matching converted D88 Disk 1. Use its unmodified 16-color Disk 2.

Download 16-color IPS

16 bytes · SHA-256 8e96ec82ddce7a382094aa48682ed5588639d3e64d71f85e305748c179c1602d

PC-9821

256-color version

Apply to the matching converted D88 Disk 1. Use its unmodified 256-color Disk 2.

Download 256-color IPS

16 bytes · SHA-256 200050f9dbf034c09473b6b0c9e179c884a930587bf69596117d8c8d9ec78220

Please read before patching

From HDM to patched D88

The supplied Black Thorne floppy images used to make these patches were HDM, not D88 or FDI. They were converted to sector-identical D88 images before patching. These IPS files target the converted D88 layout and should not be applied directly to HDM or FDI files.

  1. Make a backup of your own HDM disks. Convert them to D88, keeping the original 77-cylinder, two-head, eight-sector, 1024-byte layout.
  2. Check the SHA-256 of the converted Disk 1 against the matching base hash below. IPS does not validate its input, so stop if the hash differs.
  3. Apply the matching IPS to a copy of Disk 1 and verify the resulting hash. Leave Disk 2 unchanged.
  4. Boot a suitable PC-98 DOS environment and run SETBT.COM from the patched Disk 1 for the game's normal installation.
Exact D88 input and output hashes
16-color converted D88 Disk 1 · before
965d403ac86cf97af8d8478a8874c433e66c9a5e39dd0b880c7d1061d66101ad
16-color D88 Disk 1 · after
52832af7582c60a9750037f1e6c7a385ce973b024c71ffa8d3c125a02acfae57
256-color converted D88 Disk 1 · before
8006251f3fb3727a960651a901a62fd628649e20e4868961ee3e81e4485d7567
256-color D88 Disk 1 · after
a5771800589d7acafc318ad7a2bb11085df9ebe4f3574756f38850138e99e2d7

The patch round trip and installer success branch were verified in a 16-bit CPU emulator. Full installation and gameplay on physical PC-98 hardware or the Zet98 core have not yet been verified.