Offered here is a VERY RARE Vintage AM Expansion Unit that was issued by ARFON Microelectronics of Wales in the early 80s. This device is very similar to the VC 1020 expansion unit but with the addition of an included and enclosedinternal power supply. This was issued to be used with the Commodore VIC VC 20 computer to allow multiple cartridges to be installed at once. I would think it would also work with the Vic 20 as well but am unsure. This is an extremely RARE device; much rare than the already rare VC VIC 1020 unit.The physical condition of the unit is excellent. It allows for up to 7 cartridges to be installed at once (1020 unit allows 6) although I am not sure how you would select which one to use. It also has storage for the RF modulator in the base. When a Vic (VC) 20 is installed it becomes part of the device and almost looks like 1 unit. Does have some minor marks and rubs but really quite decent. Nice museum quality piece. These are very tough to find and are almost never offered for sale anywhere in the world. The unit does power on. This is UNTESTED but its a simple device and should work; however due to the nature and age of the device is being sold as is Parts or Repair. It has been stored in a dry place for many years. This is a 220v device. Please check out my other listings. I ship worldwide. Buyer pays shipping. Shipping is estimated. Good Luck!