The "sub" pcb side for a unisystem 1 monitor cabinet is what you would populate your eproms, cpu and ppu with.  That Location starts at 6A on the pcb.  The other side of the pcb is left empty since you are operating a single monitor unisystem.  Super mario bros does require a jumper wire on 2 pins of the cpu socket slot (search) on the main side or the use of the dummy cpu rp2a04 off memory. 

Hi,

Welcome and congrats on your VS system.  I picked up a VS system a few weeks backs, best advice is to watch john arcade's videos on burning eproms and google the vs. mame files.  You can pickup a windows based eprom burner on amazon for $55 (Signstek usb eprom), and an eprom uv light eraser for another $20, and writable eproms (eBay) M2764A.  This type of setup is a good investment for the time being until a new flash cart system (universus) is available.  The KLOV forums have folks now selling the vs PPU chips.  Some vs. game files have been modified to use other PPU chips so you have some flexibility on running different games with different PPU chips, these modified game files  can be found by searching the KLOV forums.