What's another good plugin to get for a 544 with 1A1?
I lucked onto a 544 advertised in the Santa Fe craigslist.
The 1A1 seems good for most use cases. mine is "The third model, from ??? until the end has four-sided V/cm knobs and a FET front-end."
1A4 seems good for emulating Jim Williams with lots of traces displayed...
1A5 seems like a fine one, and can use the P6046 diff probes, (but I'd have to do the cal for P6046, which is long and detailed, and I have P6046's already matched to amps that stay together and work in any scope.)
1A7A would be nice -- same features as 7A22, more sensitive than the 1A1...