ACO...
It used to be a name: The Australian Calculator Organization. Now I think it is just a loose office-moniker: not really an official name as such. Maybe it is still used within HP, or by ACO itself, I am not sure.
In the collectibles era, you know the divisions that the various products came from primarily by their geographic locations: Palo Alto CA, Loveland CO, Corvallis OR, etc. Each was responsible for some calc development at one point or another, and each had their own "personality"-- which was reflected in the products.
In the nineties, however, HP was about to go out of the calculator biz altogether. Divisions handling this were cut WAAY back, and some reorganization plans were drawn up that saw HP exiting this market altogether. Calculators got a back seat in the early nineties and from about 1990-1995 were being fitted with cement shoes, ready for the last ride. But a few sensible folk inside HP still saw a potential for calculators.
There was an HP office located in Australia, supervising design and production of some of the HP products in the Malaysian, Australian, Thailand/Singapore factories. They either lobbied for, or got stuck with, the calculator operations. I like to think they lobbied for it. They took on the name Australian Calculator Organization, or ACO, and took all responsibilities for the existing lines and new product development of HP calculators. I believe this happened around 1995(?).
The ACO's home-developed product is out there to be seen, a la the 6s Solar, (I think) the 39's, the Xpander and so on. They have had only a meager development budget, I am told, and have since been sort of lumped under the supervision of a new "Mobile Computing" division within HP.
So "ACO", if that name still applies, is where, from our standpoint, the "action" is, or rather, where it should be.
After the new administration split HP and Agilent, the ACO is on the HP half (in my opinion, a mistake). Fiorina's dedication of the HP company to internet-based customer contact and services (she came originally from Lucent) likely means that she/the company sees dedicated calculators as sort of a waning subset of the "REAL star", the PDA.
If the ACO is to continue to deliver professional numeric/dedicated tools, they'll have to prove that theirs is not just a legacy product. They've survived, in part, on the long runs of the 12c, 10b, and such for a while now...
But I have to admit, they've got a tough row to hoe... the HP that spawned the calculators is now becoming an integrated, consolidated monolith, not the same corporate culture that saw internecene wranglings over "turf" every few years. So the goals they set will be mass-market ones, not the narrowly-focused vision of isolated engineering departments.
Such an "assimilated" company would probably have kept Wozniak on, developing an Apple in-house, instead of saying "this does not fit our market needs". On the other hand, such a company would probably not have been as fully instrumental and involved as HP really WAS in developing C-MOS processes and memory and display technologies just to realize the needs and goals of "thin" markets such as test instrumentation, terminals and calculators.
Well, Cheers! to the "ACO"-- I wish it good health and prosperity, and maybe a touch of that old HP spirit and magic...