Bike died,need some pointers

Hey out there. bare with me while i give you a bit of a background and the lowdown. I just bought my first bike, a 1980 KZ750 twin have been riding it over a week now and have easily put near 750 miles on it in that time. besides some backfiring while idling and letting off the accelerator, the bike has run like a champ. today i was out for a cruise on the natchez parkway (if you are in the tennessee, alabama, mississippi area, its an amazingly beautiful ride!) and as i pulled into a stopping spot the bike died as soon as i pulled in my clutch and started down shifting. ok, backstep a bit, before the run the battery seemed sluggish getting the bike started so i kick started it.
well, after seeing what there was to see at the scenic look i tried starting back up with electric start and nothing, so i kicked it and it fired right up. about twelve miles from that is where i was getting off the parkway to head home and again when i had the clutch in it died. i couldnt even kick it this time and had to have someone come and get me and the bike. then once home i was able to roll start it, it ran for a bit, but as soon as i messed with the choke, it died and it has set since and i have decided to drink a few beers and forget about it for the evening.
any ideas? i am not a mechanic. though i wanted to try my hand at some fixing up this winter with this one, i wasnt expecting to have an early start. does this year (80) have points? i still havent been able to track down a manual for this bike either... something i want and need. but i am just needing to know what i might need to look at first.
sorry its been a long one, thanks for any help anyone can give me.

The '79 750 twin definitely has points, not sure about '80.

If your battery is flaky, it could cause this. The bike might die at slow idle because the alternator can't put out enough juice to run it and the bad battery isn't able to either. Those bikes have headlight/running lights always ON (no light switch) so the battery MUST be good enough to feed that load and the ignition as well at idle speed or the bike dies.

It could also be fuel problems.

If you just bought the bike, the best things to do for starters would be:

1) Flush the fuel system (tank and carbs) with clean gas.

2) Replace the fuel filters or install them if they are not there.

3) Drop the bowls on the carbs and clean them. On the twins, you can do that with them on the bike if you have the right length screwdriver. Hose the bowls out and also spritz the works of the carb while the bowls are off.

4)check valve clearance

5) put in new plugs

6) check cylinder compression.

7) oil/filter change if not done recently

I'm leaning towards the alternator(Dynamo).
I was having issues with my battery a couple weeks back,and it turned out that one of the 3 wires coming out of the alternator had been making contact with the rotor,and yup...chewed through it.
My battery wasn't keeping up,and after testing the 3 wires,I narrowed it down to that,and got it fixed.(soldered and heat shrink)

Charge your battery up good,and then with the bike running,get some readings(volts)off of the battery.You should be getting just around 13 volts at the battery,with the bike idleing,and over 14 volts with the bike revving at around 4k.