Sopwith is one of the earliest multiplayer PC games, but anyone who has ever tried to use the multiplayer function has invariably found it doesn't work. With the game's 40th birthday coming up this year, I decided to put the work in to see if I could finally get it working, particularly in DOSbox. Imaginot is the result. Click through for demo video:

To give some background: Sopwith itself was written as a demo program for the proprietary "Imaginet" networking system that was sold by BMB Compuscience of Canada. The system allowed a single floppy disk to be shared between multiple computers on a hardware level, and Sopwith itself works by continually reading and writing a shared file accessible by all the machines. However, since it performed raw sector-level disk access to do this, it could not be used on any other networking system.

Imaginot works by hooking the DOS and BIOS interrupts that perform low-level disk access and simulating a floppy disk in drive B:. The commands written to the file then get transmitted to other peers in the game. For communications, it reuses the Doom networking interface, so you can use any Doom networking driver (and we have quite a few). There are some further improvements I still want to make but it's complete enough for testing and Internet play.

Download can be found here.