Harry Axten of HKA Design is a hardware developer known for expanding the capabilities of classic gear like the TR-505, TR-626, TR-707 and many others. He's recently posted this video of an EMU E-Drum with custom sounds loaded, including the 909 Ride and Crash Cymbals - pitch shifting the sounds and triggering them externally.
It's exciting to think of the possibilities of this gear with new sounds on board - in the past, the available carts were pretty much set in stone, and the cost of equipment to burn your own chips was a barrier for most people. Great to see him taking this idea further!
Have a look at his youtube channel here: https://www.youtube.com/channel/UC_0YL90IoxSSYPnP-u_0Jpg