PC synch circuits are completely “dumb” – there’s no communication at all between the flash and the camera, so the camera doesn’t know there’s a flash present and is metering for the ambient light.
You can get standard hotshoe adapters for the funky Minolta Maxxum shoe, but the minolta X series flashes don’t have TTL circuitry, so there wouldn’t be a whole lot benefit to using one over the PC cord (it might automatically set the flash to the max synch speed and register in the exif data, but that’s about all, I think).
You ought to be able to use the auto setting on the flash (which uses a metering cell on the flash itself) though, if you manually set the camera to the max synch speed and the correct auto aperture for your ISO (based on the calculator on the back of the flash).