Re: [midatlanticretro] Re: Oldest working digital computer?
- Douglas <touchetek@...> wrote:
>--- In email@example.com, "Evan Koblentz" <evan@...>
>> >> I'll be interested in hearing if you guys think their claim of
>oldest is true.
>> It's the oldest digital large-scale computer. But there are probably
>some people with Simon computers from the 1950s. Those are digital,
>just not large-scale.
>I guess the ENIAC is non-function?
>Darnit. Those Brits.
Sent from my PDP 8/e.
>> Simon...none were actually produced I thought.Why do you think that?
(I don't mean the abstract Simon from the "Giant Brains" book, I mean the digital logic trainer, a la DigiComp, etc.
> I did enjoy the video, love seeing old pixie tubes in action.Close but no cigar.
Those are DECKATRON tubes: they count up AND display the number as a glowing pin in orange (neon) or purple (mixed gas). Meaning the ALU is decimal, not bi-quinary or binary.
> Close but no cigar.Close but no cigar.
> Those are DECKATRON tubes: they count up AND display the number as a
> glowing pin in orange (neon) or purple (mixed gas). Meaning the ALU is
> decimal, not bi-quinary or binary.
There were Dekatron tubes that were not decimal based, some with extra
electrodes so you could do weird numeric bases and bi-quinary
(although in this case I am pretty sure they are pure decimal).
- --- In firstname.lastname@example.org, "Jeff Jonas" <jeff_s_jonas@...> wrote:
>Oh OK! Learning something every time on this board.
> > I did enjoy the video, love seeing old pixie tubes in action.
> Close but no cigar.
> Those are DECKATRON tubes: they count up AND display the number as a glowing pin in orange (neon) or purple (mixed gas). Meaning the ALU is decimal, not bi-quinary or binary.
I'll have to look them up.
- --- In email@example.com, Mike Hatch <mike@...> wrote:
>That's very kind of you, and the sentiment is reciprocal.
> If it helps get the old stuff running - yes - even if on the wrong
> side of the pond !, all power to you, best of luck.
Any competition is definitely friendly!
- --- In firstname.lastname@example.org, "Evan Koblentz" <evan@...> wrote:
>That's great news! Very exciting possibilities.
> >> I guess the ENIAC is non-function? ... >> There's an effort afoot to take back the TITLE! Restore the ENIAC in Philadelphia!
> Context is key. :) ENIAC isn't in one piece, nor one place ... parts of it are scattered about the country, and huge fractions of it are simply gone. The plan you cited involves building a replica of most of it, whereas the Witch is mostly original. Also, the plan you cited mostly exists "on paper"; there isn't much actual effort underway.
> Here's the good news: the Mauchly/Eckert families and MARCH have a good relationship. I first met Bill M. (son of ENIAC creator John M.; Bill is the family's historian, public liaison, and himself a computer engineer) around 2006/2007. I asked for his help with some research and that went well. Then he spoke at our VCF East show in 2008. After that I helped him with some of his own research and became close with a group of historians and Mauchly/Eckert family members who are all passionate about ENIAC.
> As such, Bill is very aware of InfoAge, and there's an open invitation for him to build his replica there as part of our computer museum.
> Unfortunately our museum doesn't own any ENIAC artifacts. All we have is a picture. However we do have some UNIVAC artifacts. We have a UNIVAC 1 technical manual, several pictures, a board of tubes from an unspecified ERA/Remington system; and the majority of a UNIVAC 1219 computer from 1965.
Do you already have any good Burroughs contacts? I just bought some old Macs off of a retired Burroughs executive.
I could try to track down some early Burroughs through him if you want.
> That's the 531 character URL. Here's the 26 character:It was also covered by BoingBoing:
the Harwell Dekatron Computer ... used dekatrons for volatile memory
The machine was decimal and initially had twenty 8-digit dekatron registers for internal storage, which was increased to 40 which appeared to be enough for nearly all calculations
This site explains some details such as schematics
as a step on the way Electronics Division offered to design and build for us an automatic calculator in which the switching was done by relays (as had been done in a classic series of machines built by Stibitz in Bell Labs.) but in which the decimal arithmetic and memory were electronic, using about 800 scale-of-ten Dekatron tubes.
And there you have it from the horse's mouth: those are ALL scale-of-ten Dekatron tubes
And those metal cylinders are probably stepping relays that also tend to be in banks of 10.
- And most useful to us: the bottom right column links to the programmer's manual and flowcharts!
> And there you have it from the horse's mouth: those are ALL scale-of-tenYes, those used in that specific machine are, but not all Dekatrons
> Dekatron tubes
are decimal. The phone company used some of the oddball types due to
some of the non-decimal nature of the switching system.