This article has a striking absence, that being the name "John Atanasoff"[0], whose electronic digital calculator was seen and examined by Mauchly in 1941, and who spoke to Mauchly multiple times during the years when ENIAC was being built.
It was this connection that ultimately blocked Eckert and Mauchly from patenting the idea of the digital computer.[1]
I heartily recommend both (if you can find them) "The First Electronic Computer: The Atanasoff Story" (for a technical look at the computer itself, by Arthur and Alice Burks) and "Who Invented The Computer?" (for a history of the ABC as it applies to the patent trial, by Alice Burks).
Today's surviving UNIVAC architecture is the first transistor-based machine, the 1107, which is not compatible with any of the previous designs that all used vacuum tubes. "Only 36 systems were sold."
United Airlines remains a major customer for the UNIVAC architecture.
The first SMP Unix implementation was on UNIVAC hardware, and used the EXEC-8 kernel from OS2200 directly, implementing a Unix system call as a "shim" around it.
"The UNIX system for the UNIVAC 1100 series was built as an integrated development environment for transactions that run directly on EXEC. Unlike most other implementations, therefore, it runs not directly on the hardware but as a collection of user-level activities under control of EXEC. These obtain services that would normally be provided by device drivers, and some process creation and management services from EXEC. Any configuration supplied by Sperry, including multiprocessor ones, can run the UNIX system."
Google had never heard of Skeduflo. I hadn't either, and I once did work on critical path program using UNIVAC computers. It was apparently an analog computer for computing PERT charts. It probably never got beyond the prototype, or there would be more history around it.
That's a neat idea. I can see how it would work. A PERT chart is a time-oriented acyclic dependency graph. Each task has a duration, and tasks can be in parallel. At join points in the graph, the later end time determines the time value for the end node, and that feeds the following tasks.
So an analog computer could do this with voltage=time and resistance=duration. The picture shows a compact plugboard at the lower right. That's the dependency graph. Then there are lots of knobs, for setting task duration. For each join point, there would be a circuit to pass through the higher voltage (maybe just diodes, although diode drop would be a problem; might need an op amp). Then you have lights to tell you which path is longer at each join point. Now you can tweak the knobs and adjust the schedule. There ought to be a meter available for reading out times, but maybe that's external.
I was hoping Minnesota would be mentioned, I had an older relative that once worked for UNIVAC. I didn't realize how spread out it was.
From Wikipedia:
>The UNIVAC was manufactured at Remington Rand's former Eckert-Mauchly Division plant on W Allegheny Avenue in Philadelphia, Pennsylvania.[1][9] Remington Rand also had an engineering research lab in Norwalk, Connecticut, and later bought Engineering Research Associates (ERA) in St. Paul, Minnesota. In 1953 or 1954 Remington Rand merged their Norwalk tabulating machine division, the ERA "scientific" computer division, and the UNIVAC "business" computer division into a single division under the UNIVAC name.
I'm guessing all the coolest stuff had long since happened before my relative was there.
> Definitely not yet on the market, but envisioned by Dr. John W. Mauchly, is a miniature computer for household use that will not only make shopping lists obsolete but will also mark the extinction of the grocery clerk and the checkout-counter man. Before going to market, a woman will slip her computer into her purse (it will have an inventory of what she needs in the way of staples and supplies stored in its wafer-thin memory cells). Once at the market, she will plug her computer into a socket in a vacant “delivery alcove” and wait for the results. The computer will carry out the business of identifying itself, making the proper accounting entries in its own memory, and authorizing the charge against its mistress’ universal checking account. In less than a minute the order slides down a chute, and the housewife brings home the electronic bacon. Dr. Mauchly, who invented some of the original big computers and has already built one the size of a suitcase, is working on the pocket monster.
For a while I worked at what was then the Sperry Rand Corporation (now Unisys) which had some pride in their heritage as the descendant of the Univac Corporation founded by ENIAC inventors Eckert and Mauchly. In a glass case there was a vacuum tube circuit said to be a memory unit of the original ENIAC. No one seemed to know much about it, casting doubt on the claimed provenance of the device.
The tube circuit resembled the ones shown in the photo linked below (although none of those in the photo are from ENIAC).
If it looked like the one on the left then it was probably an ENIAC decade ring counter. It could store 1 digit from 0 to 9 and could selectively count pulses to increment the value, with carry to the next one. The 10 tubes on the right (out of 36) were the actual flip flops of the counter.
I recently read a fascinating book I found in the library by an engineer who worked under Mauchly and Eckert and talks about working on ENIAC, BINAC, EDVAC, LARC, and UNIVAC. The book is "From Dits to Bits" by Herman Lukoff.
It was this connection that ultimately blocked Eckert and Mauchly from patenting the idea of the digital computer.[1]
[0] https://en.wikipedia.org/wiki/John_Vincent_Atanasoff [1] https://en.wikipedia.org/wiki/John_Vincent_Atanasoff#Patent_...
https://en.wikipedia.org/wiki/UNIVAC_1100/2200_series
The 1108-II was the first SMP dual processor architecture that was sold commercially, announced in 1965.
The operating system launched on the 1107 is now known as OS 2200, and is still supported.
https://en.wikipedia.org/wiki/OS_2200
United Airlines remains a major customer for the UNIVAC architecture.
The first SMP Unix implementation was on UNIVAC hardware, and used the EXEC-8 kernel from OS2200 directly, implementing a Unix system call as a "shim" around it.
https://www.nokia.com/bell-labs/about/dennis-m-ritchie/other...
"The UNIX system for the UNIVAC 1100 series was built as an integrated development environment for transactions that run directly on EXEC. Unlike most other implementations, therefore, it runs not directly on the hardware but as a collection of user-level activities under control of EXEC. These obtain services that would normally be provided by device drivers, and some process creation and management services from EXEC. Any configuration supplied by Sperry, including multiprocessor ones, can run the UNIX system."
That's a neat idea. I can see how it would work. A PERT chart is a time-oriented acyclic dependency graph. Each task has a duration, and tasks can be in parallel. At join points in the graph, the later end time determines the time value for the end node, and that feeds the following tasks.
So an analog computer could do this with voltage=time and resistance=duration. The picture shows a compact plugboard at the lower right. That's the dependency graph. Then there are lots of knobs, for setting task duration. For each join point, there would be a circuit to pass through the higher voltage (maybe just diodes, although diode drop would be a problem; might need an op amp). Then you have lights to tell you which path is longer at each join point. Now you can tweak the knobs and adjust the schedule. There ought to be a meter available for reading out times, but maybe that's external.
From Wikipedia:
>The UNIVAC was manufactured at Remington Rand's former Eckert-Mauchly Division plant on W Allegheny Avenue in Philadelphia, Pennsylvania.[1][9] Remington Rand also had an engineering research lab in Norwalk, Connecticut, and later bought Engineering Research Associates (ERA) in St. Paul, Minnesota. In 1953 or 1954 Remington Rand merged their Norwalk tabulating machine division, the ERA "scientific" computer division, and the UNIVAC "business" computer division into a single division under the UNIVAC name.
I'm guessing all the coolest stuff had long since happened before my relative was there.
> Definitely not yet on the market, but envisioned by Dr. John W. Mauchly, is a miniature computer for household use that will not only make shopping lists obsolete but will also mark the extinction of the grocery clerk and the checkout-counter man. Before going to market, a woman will slip her computer into her purse (it will have an inventory of what she needs in the way of staples and supplies stored in its wafer-thin memory cells). Once at the market, she will plug her computer into a socket in a vacant “delivery alcove” and wait for the results. The computer will carry out the business of identifying itself, making the proper accounting entries in its own memory, and authorizing the charge against its mistress’ universal checking account. In less than a minute the order slides down a chute, and the housewife brings home the electronic bacon. Dr. Mauchly, who invented some of the original big computers and has already built one the size of a suitcase, is working on the pocket monster.
[0] https://time.com/archive/6625605/the-marketplace-build-small...
https://en.wikipedia.org/wiki/File:Women_holding_parts_of_th...
(This is a repost of an older comment I made)