Yes -- that is right. Back in those days, you could build the linux kernel from scratch on a laptop with 16MB of memory! I used to commute (on a weekly basis) from Boston to NYC, and you could build and boot and test a kernel between taking off from Logan airport and landing in La Guardia! I can't recall the vendor of the laptop that I used, and the internet is indicating that maybe the 16MB was an overestimate.

I think that the adjtime call went in in Linux 0.99pl15 (there were different numbering conventions back then).