Wow Ian...the beauty of the TR-707 was ..programmable..
Yes, that's true, Fran, but at the time I was just not willing to put the time in on it...if I remember correctly, it had some sort of matrix display for programming the drum hits per measure.
For my purposes, a preset box was all I needed, I think I used a Yamaha RX-120 for s short time. I had a DX-7MkII with the Grey Matter E! board, and it had a sequencer/arpeggiator that we used linked to the RX-120...it was when I was doing some segues for the local radio station.
The 808 was never a favorite, although, we have pretty decent replications of it on our arrangers...I was more into the standard drum kit sounds.
Ian