Folks!
I have a TDS784A. Pretty good condition, has options 13, 1F, 2F, 1M.
1M is easy enough to find. Extended memory, a whopping 500k memory! Whoop!
And that's it. Can't google foo the others. That is to say, I did find the options list for the 784D.
2F should be "extended waveform math". Sure enough, I can find FFT, integrals and differential math functions on the machine. So, that seems legit
13 should be RS232 and centronics. Those are indeed present on the backpanel, so that should be a match.
But finally 1F... haven't the fogiest. Anyone?