Kent Sharkey wrote:
the lowest-level language of all.
Well, not quite ... In my student days, we did an exercise with an AMD 2901 bit-slice processor development kit (if you associate anything with 'bit slice processor', I guess your grandchildren are ready to make a family by now :-)). It had 4 bits, and we had a single one available, with a microcode store of 64 sixteen-bit micro-instruction words. Programming was done by flipping 16 switches, press "Deposit", flip switches, "Deposit", ... If you made a mistake, you had to clear the entire microcode store and start from the beginning, flipping switches again. I dare say that this was programing at a lower level than assembly coding Intel processors, whether 32 or 64 bits. The technical documentation for one 16-bit mini of those days listed the entire microcode, in binary format, for the four 2901s that was hooked together as its CPU. (It might have been 2903s, it is so long ago that I am no longer sure.) There was a "Microprogramming manual" available. When I asked how many customers actually wrote their own microcode, I was told "So far, we have managed to talk everyone of them out of it" :-) (The manual was used internally, though.) It was claimed that those microcoding the VAX-780 had an average productivity of one microinstruction a day. That was years before URLs, so I do not have any link to document the claim.