Megadrive External Interrupt?

I'm new to the MegaDrive so bear with me.

Short version: does anyone know if it's possible to raise an "external" (level 2) 68000 interrupt on a MegaDrive using only the signals available on the cartridge slot?

Long version: I would like to build a custom cartridge that turns a MegaDrive into a simple computer:

1) A CompactFlash slot as a "hard disk"
2) A PS2 keyboard socket
3) A simple command-line OS
4) Boot ROM images stored as files on the CF card

So far it all looks pretty feasible, except for one small thing. I need my hardware to be able to raise an interrupt on the 68000 and I can't see how to do that without modding the host MegaDrive, which I want to avoid.

 

I don't know but go post here dude : http://www.spritesmind.net/_GenDev/forum/.

 

You can make a interrupt using a pin on the joypad port without much trouble.
I'm not sure you can send any interrupt in the cartridge>megadrive direction. It is more megadrive>cartridge to me.