What's the difference between VMU & VMS?
VMU: Visual Memory Unit, memory with LCD Screen (100 KiloBytes).
VMS: "Visual" Memory System (?), Memory without LCD screen (100 KiloBytes x4).
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Edit:
The wiki says: "The VMU, initialism of Visual Memory Unit (called VMS,
Visual Memory System in Japan or Virtual Memory Unit)", so in this case, VMS = Nexus Memory Card, Nyko Hyperpak or generic/clonic memory's with more blocks (800 usually).
Saludos!