EEVblog 1705 - The World's First Desktop Computer TEARDOWN - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: August 29, 2025, 03:19:15 am
content: The world's first desktop personal computer wasn't the Apple 1 or the Altair 8800, it was the Olivetti Programma 101 from 1965! Computer Teardowns don't get much more vintage than this.

author: kite31
author_rank: Regular Contributor
timestamp: August 29, 2025, 03:49:54 am
content: I tripped and fell at "so simple a good secretary can learn it in a few days"Although not a good secretary, I still managed to learn it in my first year of work, some years after it was released, to help me analyse some data I had requested and for which the Computer Division (as then called) could spit out a single printout then offer me no more time. I was told at the time it was something of a privilege that they were prepared to release it to me for a week.

author: squadchannel
author_rank: Frequent Contributor
timestamp: August 29, 2025, 12:03:42 pm
content: I love Ducati(748R), so I was thrilled when I found the capacitor.28:54 "WEBER 750mA" wait, carburetor?As everyone says, it's best to send it to Usagi.

author: golden_labels
author_rank: Super Contributor
timestamp: August 29, 2025, 03:55:09 pm
content: Before people start arguing, whether Programma 101 was a computer or not, mind the fight over it has started in November 1965!In November 1, 1965 issue of “Electronics”, Electronics Review sectiondescribes Programma 101, calling it “the first desk-top calculator that has some characteristics of a computer.” This opinion triggered Earl F. Gill, whoseimmediate response has been printed in the November 15th issue:Quote from: Earl F. GillThe magazine seems to admit a miscommunication occurred:QuoteBut, sincesomeone is wrong on the internet… erm… in the printed magazine, this didn’t end here! InJanuary 24th issue next yearwe have a next post. From nobody else butPerotto himself!Quote from: Pier Giorgio PerottoNow, you all may join the 60 year old thread!

author: darrellg
author_rank: Unknown
timestamp: August 29, 2025, 04:04:26 pm
content: Quote from: golden_labels on August 29, 2025, 03:55:09 pmI love this 60 year old flame war! Thanks for posting.

author: SeanB
author_rank: Super Contributor
timestamp: August 29, 2025, 05:59:40 pm
content: It is a computer, in that it stored a program, and could execute and branch completely based on input data, or results from previous calculations. Mechanical in part, but it still is a computer nonetheless. Tied to using the things Olivetti was good for, the printer for output, and a mechanically debounced keyboard for solid data entry from decades of building calculators, and needing to have a reliable input switch that would not give false keypress inputs no matter what. If they had put in a display it would have been nixies, though adding that would have been a big cost bump, needing an external case that would carry the main bus out to have the memory for the print line latched to drive it. more lines would have needed another equal size unit, to have the memory and logic to emulate the paper feed, and move the results up each time a new line was printed, difficult to do when a single flip flop required 2 transistors, 4 diodes and at least 6 resistors to do it, which meant at least 4 cordwood modules per bit, and 10 per display line per position.

author: MK14
author_rank: Super Contributor
timestamp: August 29, 2025, 07:15:17 pm
content: The LINC from 1962, seems to be an earlier desktop (personnel) computer. Also, it seems to be a proper computer, rather than a programmable calculator, with some computer capabilities.Edit:BUT, ...Quotehttps://en.wikipedia.org/wiki/History_of_personal_computersSo it depends on ones definition, on if it has to be fully contained on the desk. If so, there were still earlier ones, that did, but they then replaced the entire desk (LGP-30).So discussing which one was first, is perhaps a big can of worms.

author: Haenk
author_rank: Super Contributor
timestamp: August 30, 2025, 06:40:18 am
content: I'd define it as the first "fully integrated desktop computer", by "input-operation-output" being combined into one portable machine, needing just a power cord to be fully operable.Funny enough, by that definition, the majority of the "modern" computers do not meet this criteria.

author: MK14
author_rank: Super Contributor
timestamp: August 30, 2025, 08:37:38 am
content: Quote from: Haenk on August 30, 2025, 06:40:18 amThe problem (as you already mentioned), is that the Original IBM PC 8088 4.77MHz, from 1981. Strictly speaking, could have a large CPU/computer box, perhaps on the floor, the monitor and keyboard on the desk and perhaps other stuff, such as printers/external-disks etc, either on the desk or to the side (not on the desk) somewhere.But clearly, the original IBM PC, has to be the 'gold standard' definition of a desktop computer. Although even that could be disputed.But in real-terms, it is generally accepted (I think), that the original IBM PC, is the thing which started the big computer revolution. Where Mainframe/mini computers, moved from being in air-conditioned computer centres, to almost everyone having computers, both at home and on their office desk.But, other inventions, such as transistors, integrated circuits, microprocessors, PCBs, Hard Disks, Networks, The internet, Graphics/video cards, monitors etc. All played their part as well.I think really, you can just argue the point, that almost anything, started certain technological revolutions off.There does seem to be a concept, that programmable calculators, are not really full/proper computers, and just a programmable calculating computer, without some of the functionality of a proper, full general purpose computer.

author: UnijunctionTransistor
author_rank: Frequent Contributor
timestamp: August 30, 2025, 05:59:14 pm
content: Olivetti was at the time, the leading company of the fabled Ital-Design industrial movement.This device is a prime example of such design. Sleek, striking and a showcase of craftsmanship. A tour de force in mechanical design.

author: sanleontexas
author_rank: Contributor
timestamp: August 30, 2025, 07:04:18 pm
content: Then you'll also need to consider the IBM 5100 which came out in 1975,in which all components were contained within the case: keyboard, display,and tape drive(parallel format tape cartridge).

author: Simmed
author_rank: Frequent Contributor
timestamp: August 30, 2025, 07:16:09 pm
content: someone got an emulatornow everyone can play at home

author: ferdieCX
author_rank: Regular Contributor
timestamp: August 30, 2025, 11:54:36 pm
content: The keys of the electromechanical keyboard of the P101 can be pressed only if the motor is rotating and the logic enables it.The large S key behaves as an "Enter" keyI worked at the service department of Olivetti in Uruguay between 1979 and 1984.As far as I know, the transistors where equivalent to the 2N706.They were also fitted in the P203 and the Auditronic 770 accounting machines, and also in the UME-2 multiplier unit for the Mercator, a mechanical programmable accounting machine.

author: axantas
author_rank: Regular Contributor
timestamp: August 31, 2025, 07:38:58 pm
content: Fascinating - I really like your teardowns, Dave - this was very special - you usually do not get this shown.If you want to see the real programma 101 running - take a look here:

author: jonovid
author_rank: Super Contributor
timestamp: August 31, 2025, 08:49:06 pm
content: logic schematics in Italian -not the complete machinehttps://hack42.nl/mediawiki/images/b/bd/Legenda_fogli_logici.pdfhttps://hack42.nl/wiki/Olivetti_Programma_101_Introduction_to_logic

author: Brumby
author_rank: Unknown
timestamp: September 01, 2025, 03:05:46 am
content: Why all the vertically mounted resistors? Think thermal design!!

author: golden_labels
author_rank: Super Contributor
timestamp: September 01, 2025, 05:10:40 am
content: Vertical mounting is cordwood packaging. At the time it would be the pinnacle of high-density component packing, unless one could afford the recently invented silicon chips.NASA’s report(see p. 9), showing a module reaching “130 components per cubic inch.”January 26, 1962 issue of “Electronics” with an article aboutassembling cordwood modules into magazines(p. 74).May 17, 1963 issue describingtrouble with production of these modules(p. 68).Apollo’s SCS modules were built using welded cordwood(p. 82 in October 17, 1966 issue of “Electronics”), and Ken Shirrif made somebeautiful X-rays and analysis of cordwood modulesfrom the same project.SomeFlyball modules(page by Jerry Proc) — basically cordwood modules in epoxy.

author: 5U4GB
author_rank: Super Contributor
timestamp: September 01, 2025, 06:57:14 am
content: Quote from: golden_labels on August 29, 2025, 03:55:09 pmThat's always the case with any claims of the world's first X, someone will inevitably pop up to point out that the little-known Noodleheinz Mk.3 predated this by more than four years.

author: UnijunctionTransistor
author_rank: Frequent Contributor
timestamp: September 01, 2025, 03:41:12 pm
content: What an exciting time to be in the electronics profession during the 1960s and early 1970s!Fueled by both the Cold War’s and Space race, electronics advanced at truly unprecedented levels.There were literally thousands of small companies manufacturing electronics-related hardware and components, and with them boundless opportunities for young engineers entering the labor market.Every time one would receive the latest issue of an electronics magazine, there was a wealth of product, circuits and components to be discovered.It wasn’t only military/aerospace applications, the US and many Western European countries still had a robust consumer electronics industry, although it was being rapidly eroded by the cheaper (and better) Japanese products.

author: GLouie
author_rank: Regular Contributor
timestamp: September 07, 2025, 07:17:04 am
content: I still have my Olivetti magnetic memory strip from using our high school's Olivetti P602 (I assume a successor to the Programma 101) circa 1971. A big deal back then, but we couldn't get much time on it since there was only one unit for the whole school (about 1500 students).

author: Sorama
author_rank: Frequent Contributor
timestamp: September 07, 2025, 07:36:30 am
content: My father (as the owner of his company) bought two Olivetti P105 in the seventies.I was a kid back then, but I remember there were issues with ESD destroying chips.For the next 30 years I was responsible for the IT park of his company and bought (around 1986) some XT pc like M24, later on M280 which was a AT board.

author: Simmed
author_rank: Frequent Contributor
timestamp: September 07, 2025, 09:24:25 am
content: Quote from: temperance on August 31, 2025, 06:07:58 pmsold to GE

author: Simmed
author_rank: Frequent Contributor
timestamp: September 07, 2025, 09:54:27 am
content: Quote from: golden_labels on September 01, 2025, 05:10:40 am00:00 intro00:37 expedition to the moon08:58 MIT/IL guidance & nav contract19:36 apollo IMU schematics22:54 design changes25:24 block 2 computer25:59 computer comparison32:50 apollo 2 IRIG (the gyro)35:30 packaging methods36:03 cordwood packaging36:28 CSM GN&C system testing (IL7)37:35 lunar module40:50 apollo flights45:11 apollo 848:10 apollo 1151:00 apollo 12 onwards

author: Wollvieh
author_rank: Contributor
timestamp: September 22, 2025, 01:22:59 am
content: Quote from: 5U4GB on September 01, 2025, 06:57:14 amEven such an insignificant invention as putting a hot wire in a glass bottle attracted envy.https://en.wikipedia.org/wiki/Heinrich_G%C3%B6belQuote from: golden_labels on September 01, 2025, 05:10:40 amAbsolutely. Just a few years ago e.g. radios were still wired with soldering strips and no printed circuit at all. As that NASA guy (?) in that video pointed out you just "drill holes in a block, drop the parts in and weld the connections." Olivetti would solder instead of weld and leave the block in the factory.The ideas Dave mentioned for size reduction would save only a few percent. Surely not a third or a half, which I would consider a reasonable improvement to go into the effort of redesigning everything.It's like deleting unused Files in Windows 95 to save 1-2% of hard disk space after a days work.

author: 5U4GB
author_rank: Super Contributor
timestamp: September 22, 2025, 01:59:02 am
content: Quote from: Wollvieh on September 22, 2025, 01:22:59 amIn any case everyone knowslightbulb was invented by Soviet Union.

author: golden_labels
author_rank: Super Contributor
timestamp: September 22, 2025, 03:11:30 am
content: In theNational Museum of Technology in Warsaw(1)there is an big room. That chamber is entirely dedicated to what feels like trying to tell visitors Poland created everything.Some are “technically true,” likeKazimierz Żegleń’sinvolvement in designing a bulletproof vest. Some, likeMalinowski’s work, are engineering achievements, but put out of context and giving them too much credit. Most are just shifting the terms, ignoring the entire wider perspective, or presenting a minor improvement as something much greater than it is. Somehow a lightbulb is not there, if I recall correctly.Fortunately the rest of the museum is more reasonable.(1)Don’t be deceived by the article consisting of two paragraphs only. The museum is not that small or unimportant!

author: 5U4GB
author_rank: Super Contributor
timestamp: September 22, 2025, 03:52:01 am
content: Oh, I didn't know Poland did that too. I made the Soviet Union joke because they seemed to do it with everything, including stuff where the Soviet "invention" came after someone else's, e.g. the Su-24 copy of the F-111 and bits of the Mirage G8 where they proudly announced that the Americans had "confirmed the correctness of the chosen decisions when creating the Su-24". Or, in the case of the Yablochkov Candle, before the Soviet Union even existed.

author: shapirus
author_rank: Super Contributor
timestamp: September 22, 2025, 01:45:57 pm
content: You should send it to Mend it Mark. He can bring it back to life no doubt.

author: golden_labels
author_rank: Super Contributor
timestamp: September 22, 2025, 09:45:07 pm
content: Quote from: 5U4GB on September 22, 2025, 03:52:01 amOne of the important things history taught me, is that history has always been heavily distorted to serve the contemporary narratives. The history of science and technology is no exception. Neither is any place an exception — just a matter of time and needs. For many places it simply didn’t happen yet, by pure coincidence. But wait long enough and I’d bet we’ll hear Copernicus was Australian.

author: kite31
author_rank: Regular Contributor
timestamp: September 23, 2025, 01:11:03 am
content: Quote from: golden_labels on September 22, 2025, 09:45:07 pmWell he was planning to emigrate before he heard that everything here is trying to kill you so he stayed home with the wolves and bears. We might have had the rainbow-serpent-centric model.

author: 5U4GB
author_rank: Super Contributor
timestamp: September 23, 2025, 05:11:15 am
content: Quote from: golden_labels on September 22, 2025, 09:45:07 pmWhat, "Brekky" Copernicus from Bondi? Of course he's Australian! Next thing you'll be telling us your museum in Warsaw is claiming he was Polish.