The VIC-1010 is a multi-port cartridge expansion device for the VIC-1001. It allows up to six cartridges to be plugged in simultaneously. Of course, the cartridges must be programmed in a way that they will work with one another, or at least be able to co-exist peacefully (not step into one another's memory space being the primary concern, I believe). So where it works well is memory expansions combined with programming expansions.

As a small bonus, it also has a power cord, and can pass the power through to the system, so you no longer need that bulky external power adapter. I'm not positive, but I think this feature will only work on the older style VIC-1001s that have the internal PSU with the external transformer.

You plug the VIC-1010 into the VIC-1001's internal cartridge slot, and add the cartridges to the external slots of the VIC-1010. The resulting footprint is... bulky and awkward, for sure. You can reasonably safely put your drink in the space on the right, I suppose. In a carefully constructed environment dedicated for VIC-1001/VIC-1010 usage, you could probably use some of the space in the rear to place your monitor (but definitely not all of it, as cables have to come in and out of the VIC-1001). In my sort of makeshift, general computing purpose environment, I had to hang about 30% of the VIC-1001 off the desk.

The below is a simple use case for the VIC-1010. I picked up a VIC-1001 16KB memory expansion cartridge and a Programmers' Aid cartridge. If you plug them individually into the VIC-1001's internal cartridge slot, they have the below respective effects on the system.

But utilizing two slots of the VIC-1010, you can combine them to get an extra 16KB as well as the Programmers' Aid expansion.

The 16KB memory expansion cartridge was in good shape with original box.