Mosaic Electronics has introduced the RAMmaster 32 for the VIC-20 computer. RAMmaster 32 includes a built-in expansion port, a pause switch, a write protect switch, and a relocatable memory block.
The unit, which adds 32K of memory, also has a disabler switch so cartridges can be removed without turning off the computer. RAMmaster 32 is expected to sell for under $150.
No I didn't actually. Just like you I found nothing on the switches, but I figured most of them out.
I have no idea what the jumper block does either.
All I know about how it works was in that thread you found.