From magazine advertisement, May 1982
A low cost stand alone printer which will be almost essential for your larger programs will be launched in the Spring of 1982. The power plug for this unit is already on your expanded system.
Slots have been left to allow normal use of the cassette socket, disc socket etc., which will still run normally with your expanded system.
EXPANDABLE TO 7 CARTRIDGES
You will now be able to use up to seven cartridges to expand from your basic Vic 20. These
can include RAM memory expansion up to nearly 30K of usable memory, ROM cartridges with packaged programs, user expansion cartridges, printer software, disc software, RS232, IEEE interface, line expansion firmware and many others - besides of course all your games cartridges.
ARFON EXPANSION MEMORY Immediately available from Arlon in cartridge are 3K RAM +2 sockets, 8K RAM, 16K RAM, 8K ROM,16K ROM. Also a basic Vic simulator cartridge to allow tape and cartridge use without altering the system.
VIC 20 Expansion System
The Arlon Vic 20 Expansion System is a finished metal cased unit that integrates your Vic 20 with an expansion board for up to seven cartridges and a toroidal power supply (fully enclosed) to give you sufficient power for any expansion and also to power the Arfon Vic Printer. Your Vic and its screen modulator are incorporated into the expansion system to produce one unit and there is an optional lid that covers the expansion area and allows your T.V. to sit on top. Access to the various input sockets on your basic Vic 20 is not restricted while it is in the expansion unit.
Stocks are available now through your own Vic Dealer.
Expansion board in cabinet designed for Commodore VIC-20 which allowed the use of up to seven cartridges instead of one; so you could add additional RAM/ROM memory, perhaps an I/O interface and a game or programming cartirdge.
May have been more useful in game development rather than gaming itself.