Re: Analog Computers - General description
- --- In firstname.lastname@example.org, Ken <kenzolist@...> wrote:
> I just happened to have discovered this great video a couple of days ago. It's a 50's US Navy instructional film about the mechanical computers they used. It's really eye-opening and very high quality. (It gets to the meat about two minutes in.) For me, it demonstrated the analog/mathematical approach, in contrast to the digital/logical approach I grew up learning.http://www.eugeneleeslover.com/VIDEOS/fire_control_computer_1.html
> - Ken
It looks like the site linked above is a primary Web source for WWII and later Naval fire control computer documents. It may be the original source for the video referenced above, or certainly an earlier one.
These control computers used rotational position (radius vs angle) as means of expressing an analog function. One input variable was a cam on a shaft; two input variables was a surface on a cylinder. By cascading, you could have several variables per output. The video series shows this, and the Navy textbooks on the site above explain further.
Mechanical computers like this were "programmed" by manufacture; one design equals one program. Electronic analog computers were programmed by wiring panels and adjusting components, as well as by design or by hard-wire. Hybrid analog computers, made the connections and adjustments digitally.
I knew nothing about the above, until I did some Web searching based on the reference first given. It's good to see more ancient technology on the Web. In this case, advanced WW II technology, digitized from books and films.
> http://www.eugeneleeslover.com/VIDEOS/fire_control_computer_1.htmlI think some of these are originally from the Historic Naval Ships
> It looks like the site linked above is a primary Web source for WWII and
> later Naval fire control computer documents. It may be the original source
> for the video referenced above, or certainly an earlier one.
Association. There is a group of us ship geeks that are also trying to
save and archive the technology, bitsavers style.
> These control computers used rotational position (radius vs angle) asThere is also a class of fire control computers that used linear
> means of expressing an analog function. One input variable was a cam on a
> shaft; two input variables was a surface on a cylinder. By cascading, you
> could have several variables per output.
displacement of levers and linkages, rather than rotation. These
machines were much cheaper to make, but not quite as accurate. And of
course, there were hybrids of all sorts. I had a small collecton of
small machines and assemblies at VFC East number 2.
Trivia - there are two Mk 4 Torpedo Data Computers still in active
service, in the Taiwan Navy. They have been in near continuous service