inhabitor/mamelink

mamelink

A compatibility shim for Lucasfilm Games' "fastlink", using a MAME plugin to implement similar functionality.

Building

Run make. Assumes a POSIX-like environment. Works On My Machine, totally untested on anything besides Linux.

Booting reno

Run ./start. Assumes that mame is in the current path, with C64 ROMs installed. MAME will start, and you will probably need to press a key to start the emulated C64 booting. Once the C64 has completed startup, reno will automatically begin uploading, and when it is complete, you will see the command SYS2122 automatically be entered into the emulator. After a few more seconds, Reno will start.

How It Works

It's a terrible, awful, very bad, no good hack, but it does the trick and should hopefully be portable, even to an enscripten-type browser environment. To send a command to the mamelink plugin, the mamelink.c library creates a file called mameplugins/mamelink/linkin with the request. The plugin checks for the existence of this file constantly. Once it is able to open it, it executes the instructions it finds, creates a file called mameplugins/mamelink/linkout with any response, and deletes mameplugins/mamelink/linkin. The mamelink.c library waits for the linkin file to be deleted, reads all of the data out of linkout, if any, and deletes it.

Some amount of energy was put into avoiding race conditions but not a lot. Try not to have multiple programs poking at C64 memory at the same time. This seems unlikely to happen in practice, at least.

Why did you do it like that

Because every sensible, normal way of doing it was broken thanks to Lua's underpowered standard library, MAME's requirement for non-blocking I/O, and the weird not-quite-acceptable socket support that MAME provides in its plugin interface. (You can only accept a connection from a single client at a time, and there is no way to determine if a client has disconnected.)