I started working on building sites, not as a full-time surveyor, but had to learn doing many of the typical surveying measurements, just around the time the "technical revolution" came, early 1980's.

#1 - laser (or whatever) distance meters, until then there were only Invar stadia rods and staffs [0]

#2 portable calculators (before the ubiquitous HP-11c, there was the HP-67 or 97, but right until then it was logarithms books and manual calculations)

Then, like only a few years later, I believe 1989 or 1990 came: #3 "real" total stations, with an actually working interface to computers, that changed once again the way we could work, much, much faster [1]

Still, it happened more than once to need (for one reason or the other, dead batteries, tools shipped for revisions, and similar) to need to do manual measurements and surely you need to have your basic trigonometry brushed up.

[0] here is an early Kern one, it costed (not the "full" E1 deopicted, only the DM503 + a "conventional" theodolite) at the time around 32 or 34 millions Lire, more or less like 2 years of a surveyor wage:

http://www.dehilster.info/geodetic_instruments/1984_kern_e1_...

[1] getting one of these at the time:

http://www.dehilster.info/geodetic_instruments/geodimeter_sy...

particularly the servo-operated version was a surveyor's dream, bordering with "sheer magic".

The HP-48x with a COGO card in the slot was a big advance for me; I learned on a Wild T3 theodolite, so advanced total stations with a data colletor such as the Leica were a big step up in productivity as well.

Yep, but the 48 came out a few years later, in the early '80's all we had were 67 and 97, then the 11C that was actually "portable" and with everlasting batteries, the "main" product at the time was the 41 but it was heavier and bulkier (and costed a lot more than the 11C, which was also nearly indestructible, I mean we had a couple of times wheel loaders passing on one of them and it came out only slightly bent in one of these incidents).

Right after the 41 and 11c, but before the 48 came the 28C (which also costed an arm and a leg, but I still have my beloved 28C in use, prefectly working, some thirty years later, so it wasn't such a bad investment ).