I make cartridges for the SCI Tom drum machine.
They have 16 banks, so its like having 16 regular carts in 1. The banks are selected with 4 switches.
The banks include the 4 SCI carts, TR-909, TR-808, TR-707, TR-606, DMX, LinnDrum, Simmons and some various banks.
Cost is $120 + shipping.
For an additional fee I can make banks made from your own samples.