Yo Wrangler:
For sure, you are just seeking an answer LIKE I look for everyday regarding the art of recording good stuff.
You have the 2816 -- a good box -- it will give you really good sounds once you get the hang of it -- the manual is weak but it will get through to you if you read and read.
Drums: I use a drum machine. I just run it right into any channel I want. Now, drum machines can be programmed and you can write out every measure; however, it takes a long time to write the drum sequence. So, I just use the pre-sets which are very flexible and creative and you can always add beats on other tracks, like cymbals, knocks, bangs, etc.
With any type of drum delivery, you need to plug it in to the recorder and the source must generate sound either line level or you can run it through a mic pre for even better sound.
So, if I read you right, you need a drum machine or something "live" to do drums. Live is much tougher to record. A simple drum machine can get you through lots of good stuff. I use the Boss 770; but, I started with a Yam drum box, then an Alesis SR-16 -- the Boss is the best of the three -- technology just keeps getting better but drum machines kind of took a rest for a few years.
I'd suggest you try to get an audition of a drum machine at a vendor or from a friend. Piping it into your 2816 is no problem. If you have problems with the 2816, give it time. Also, check page 12 on your manual which tells you HOW TO shut down the 2816.
You will also need to consider getting a UPS power back up. It does mention somewhere in the manual that if you lose power while recording and have no power back up, you can blow the Hard Drive or lose everything on the hard drive. It's a small investment for the protection it offers.
Hope this helps you out and let me know if I can offer any help with your 2816.
Green Hornet