Can anyone explain the basics of the smartlink subsystems? My comy of MM is on loan at the moment and a character I'm working on might want to min/max the subsystems to save that little bit of essence.

For example, what are the in game effects of taking the processor, induction pad, and the display link but leaving off the simsense rig?

-- Dashifen --

The subsystems are all required unless you have other ware that duplicates the functionality.

You can drop the limited simsense rig if you already have a simsense rig of some sort.

Processor: No replacement. This makes everything work.
induction pad: This could be replaced by a datajack, and then you get to plug your gun into your head (which, IMO, looks a lot cooler anyway). Pretty much, any way of connecting your gun to you would work.
display link: Smart goggles or any sort of visual uplink should work.
simsense rig: Anything that uses a simsense rig... The only thing I've seen that officially lists this is the simsense rig and recorder, so simsense stars can save this .2 essence. (non canon) You could say maybe a VCR or skillsoft rig have simsense rigs (I don't believe either list it as being part of the setup, but I can't imagine how they'd work without). But that's GM's call.

Can you work without a simsense rig? Canon says absolutely not, I'd rule you could in part. The simsense rig would give you the little spot to tell you where your gun is currently pointing, and maybe could tell your body things, like the best stance to take. Without the rig, they'd have things like being able to eject the clip, switch modes etc. The rangefinder and PSS might still work, but you wouldn't get any bonuses to actually firing.

Everything is really up to the GM, and don't forget you don't get the full bonuses when using any non-cyber. Also, don't forget that if you depend on another subsystem, the SL and the subsystem have to be the same grade.

Here's my take.