[HN Gopher] Altair at 50: Remembering the first Personal Computer
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       Altair at 50: Remembering the first Personal Computer
        
       Author : rbanffy
       Score  : 87 points
       Date   : 2025-05-02 11:03 UTC (11 hours ago)
        
 (HTM) web link (www.goto10retro.com)
 (TXT) w3m dump (www.goto10retro.com)
        
       | berlinbrowndev wrote:
       | Cool I always thought the first PCs were like the TRS or
       | Commodore 64 computers.
        
         | rbanffy wrote:
         | There is some controversy - you could actually use a TRS-80, an
         | Apple II or a PET right after taking it out of the box.
         | 
         | I think that, if we define a personal computer as a machine
         | that is designed for a single interactive user, the LGP-30
         | would be a good candidate. It was not, however, a home
         | computer.
         | 
         | For me, a personal computer needs more than switches and LEDs
         | as its UI. With a serial port, a terminal, and a monitor
         | program in ROM, the Altair would qualify.
        
           | anthk wrote:
           | TRS-80, AII and the PET came later. You were right on the
           | peripherals. Instead of a serial port, I'd set a TV output
           | with a keyboard as an input, and the Altair would get far
           | more sales.
        
             | fortran77 wrote:
             | The people I know who put together Altairs in 1975 used
             | ASR-33 teletypes as terminals to run BASIC.
        
               | TheOtherHobbes wrote:
               | Teletype and all, the Altair looked and worked like an
               | cut-down entry-level version of the minis that were
               | popular in engineering and science.
               | 
               | Not as powerful as a PDP-8, but less than a tenth of the
               | price.
               | 
               | It was the perfect aspirational project for the
               | electronics hobbyist community of the time.
               | 
               | The fact that you could barely do anything with it wasn't
               | the point. It was a real computer you could set up at
               | home and use without time restrictions or hourly billing.
               | 
               | The S-100 bus market turned into a preview of the PC
               | market. S-100 systems soon sprouted real terminals,
               | floppy drives, and workable memory, and began to appear
               | in the offices of accountants and other non-tech
               | professionals.
               | 
               | The IBM PC probably wouldn't have happened without it. It
               | normalised relatively affordable computing, and the idea
               | of a third party market of expansion cards on a standard
               | bus.
        
             | SoftTalker wrote:
             | A TV output means you need to create (and have memory
             | dedicated to) the video. A serial port is much simpler.
        
               | rbanffy wrote:
               | A 16x64 character screen like the TRS-80 needed 1k of
               | RAM. IIRC, the Altair didn't have that much memory out of
               | the box.
               | 
               | The video memory would either be in the computer or the
               | terminal. At least if it were in the computer, you could
               | use it for other stuff.
        
           | SoftTalker wrote:
           | Did it not have a serial port? Would have assumed that
           | connecting it to a terminal or teletype was the standard
           | thing.
        
             | whartung wrote:
             | My first computing experience was with an IMSAI 8080 that
             | class assembled the year before.
             | 
             | It had a keyboard and video board, rather than a terminal.
             | The monitor was open chassis to boot (ah the old days when
             | we didn't protect children from lethal electricity).
             | 
             | It had a ROM monitor and cassette tape. You had to type in
             | (in hex) a short machine language program into the monitor
             | to load BASIC from a cassette. We simply never turned it
             | off.
             | 
             | I tried ti enter the bootstrap through the front panel
             | once, but I made some mistake, and it didn't work. It was
             | an awful enough experience I never tried again.
        
               | jmount wrote:
               | Ah man- the power supply in the IMSAI 8080 was scary
               | enough, plus you had the monitor power supply open. Fun
               | times- the "book" sequence on ours was "fat finger in the
               | paper tape reading software, read the cassette IO
               | software from paper tape, load BASIC from cassette, and
               | good to go."
        
             | ebruchez wrote:
             | One of the interesting aspects of the Altair was that it
             | was based on a bus called the S-100 bus. You would have a
             | CPU card and a memory card at least, but everything else
             | was optional. The serial board was separate, and strictly
             | not absolutely necessary to play with the computer, since
             | you could enter simple programs directly from the front
             | panel.
        
               | SoftTalker wrote:
               | I remember S-100 from when I was a kid. Never was hands-
               | on with that hardware but there were all kinds of ads for
               | cards in Byte magazine and others. Seemed like you could
               | get a card for almost anything in S-100 protocol.
        
               | ebruchez wrote:
               | That's right. There are still S-100 enthusiasts who are
               | maintaining and developing S-100 cards, see
               | http://www.s100computers.com/ (does not seem to respond
               | correctly to HTTPS right now).
        
             | maj0rhn wrote:
             | We had an Altair at home, that my father assembled from a
             | kit. That version did not have a serial port. It had only
             | the switches on the front panel. I did succeed in inputting
             | some programs and in having them run. But of course it was
             | appallingly limited.
             | 
             | The serial port was its own separate board.
             | https://www.youtube.com/watch?v=RaYTd3dbXeM
             | 
             | There were two very clever I/O ideas that emerged for the
             | Altair: (1) A radio on top of the housing would pick up a
             | signal, allowing audio output! (2) A cassette tape recorder
             | could be used as an external storage device, though I
             | forget how it interfaced... the serial board, I think.
        
           | dowager_dan99 wrote:
           | keep the historical context in mind. There were people who
           | wanted a computer at home and people who wanted to bring home
           | the experience they got with access to powerful mainframe &
           | minicomputers at work or school, so there was both a push to
           | build your own computer and a desire to build IO devices like
           | teletypes. The combo, all-in-one is the real revolution (IMO)
           | that you got with the Apple II or the Sol. The TRS-80s and
           | PETs feel a lot more like early commercialization in
           | comparison. Woz was motivated by showing off what he could
           | create, because that's how he communicated. It makes sense
           | that a keyboard and TV - with graphics - shows off way
           | better, same with being able to program in basic "... for
           | $300 you can build a computer that's so good you can type
           | programs on it and run them..."
        
         | Pet_Ant wrote:
         | You might want to look at the Sol-20, Micral N, and Kenbak-1 as
         | well. From 1971, the Kenbak was a _personal_ computer, but not
         | a personal _micro_ computer.
         | 
         | The Wang 2200 looks most like we'd expect a personal computer
         | to look like, but the price range was not home-friendly (~$50k
         | today).
        
         | chasil wrote:
         | The Intel line was fathered by the Datapoint 2200; they
         | implemented the CPU in TTL logic boards.
         | 
         | https://en.m.wikipedia.org/wiki/Datapoint_2200
         | 
         | The 6502 line came out Motorola's failure to "indulge" their
         | employees in a low-cost 6800, thus unintentionally fathering
         | MOS Technologies.
         | 
         | https://en.m.wikipedia.org/wiki/MOS_Technology_6502
         | 
         | The 6502 was extremely inexpensive. The first implementation
         | was the KIM-1, so this is the first on that side.
         | 
         | https://en.m.wikipedia.org/wiki/KIM-1
        
         | mixmastamyk wrote:
         | Commodore had the PET in the late 70's, and the Vic-20 before
         | the 64 in the early 80s.
         | 
         | Apple had the II in the late 70s, and before that was the
         | Altair.
        
         | rahen wrote:
         | "Personal computer" can refer either to a small-form computer,
         | in which case the Olivetti P101 was likely the first in 1965
         | (the PDP-8/E was also a contender), or to a microprocessor-
         | based computer, in which case the Micral N holds that title in
         | 1973.
         | 
         | The Altair, in 1975, was the first commercially successful
         | personal microcomputer.
        
       | igtztorrero wrote:
       | The Altair didn't survive for very long, but essentially being
       | responsible for the creation of Microsoft is a pretty Big Deal.
       | 
       | Bill Gates: "Popular Electronics" magazine cover of January 1975
       | change my life"
       | 
       | Paul Allen write the simulator on Harvard PDP-10, Bill Gates
       | write main code of Basic, Monte Davidoff write Math package. They
       | coded day and night during 2 months.
       | 
       | Micro-Soft was born.
        
         | JSR_FDED wrote:
         | Similarly it inspired the start of Apple!
        
           | rbanffy wrote:
           | Apple got a couple things right - the II had a keyboard, TV
           | output with graphics, and plug-and-play slots (no fiddling
           | with jumpers and dip switches like s-100 and PCs): each card
           | had a well defined space for IO and ROM.
        
             | thesuitonym wrote:
             | Note that the Apple I was a kit computer that didn't come
             | with anything other than the board and the chips. Not even
             | a case! It's not really like Jobs and Woz had the brilliant
             | idea that nobody had thought of before to include the
             | accessories, it's just that the prices had come down to the
             | point where a person wouldn't balk at buying a preassembled
             | computer with a keyboard, display and a couple of floppy
             | drives.
        
               | rbanffy wrote:
               | > It's not really like Jobs and Woz had the brilliant
               | idea
               | 
               | They understood that, if the computer had a keyboard and
               | a professional-looking case, a lot more people would buy
               | one.
        
               | Someone wrote:
               | Jobs certainly understood that, but Woz?
               | 
               | https://www.apple2history.org/history/ah04/:
               | 
               |  _"Jobs thought the cigar boxes that sat on the ...
               | desktops during Homebrew meetings were as elegant as fly
               | traps. The angular, blue and black sheet-metal case that
               | housed Processor Technology's Sol struck him as clumsy
               | and industrial ... A plastic case was generally
               | considered a needless expense compared to the cheaper and
               | more pliable sheet metal. Hobbyists, so the arguments
               | went, didn't care as much for appearance as they did for
               | substance. Jobs wanted to model the case for the Apple
               | after those Hewlett-Packard used for its calculators. He
               | admired their sleek, fresh lines, their hardy finish, and
               | the way they looked at home on a table or desk."_
        
               | rbanffy wrote:
               | > Jobs certainly understood that, but Woz?
               | 
               | This is why we need to surround ourselves with people we
               | don't always agree with.
        
         | reaperducer wrote:
         | _Altair didn't survive for very long,_
         | 
         | The company sold itself to Pertec for what was a very good
         | amount of money back then.
         | 
         | In HN terms, it was a successful unicorn bro exit.
        
           | dowager_dan99 wrote:
           | and if I remember it correctly Roberts used the money to buy
           | a peanut farm? Is that equivalent to a tech bro buying the
           | coast of California or an island?
        
             | bbarnett wrote:
             | Did he use all the money, or some?
        
               | reaperducer wrote:
               | The property records are probably online. Go nuts.
        
               | bbarnett wrote:
               | My point was, buying a peanut farm != spending every
               | penny you owned on the peanut farm. It simply could have
               | been what he desired, enjoyed. He could have socked away
               | way more.
               | 
               | The comment I replied to alluded to said peanut farm
               | being (forgive me) peanuts compared to a coastline.
        
         | dowager_dan99 wrote:
         | and the fact that MITS couldn't keep up with demand gave birth
         | (IMO) to the 3rd party (licensed and unofficial) peripherals
         | ecosystem.
        
       | shakna wrote:
       | I was completely distracted by the magazine cover. The calculator
       | being advertised there, and the wording, caught my attention.
       | 
       | The magazine issued is available here [0].
       | 
       | Apparently, it really was wiring up an entire calculator.
       | 
       | > ... Start assembly by installing and soldering into place the
       | fixed resistors. Then proceed to installing the three
       | electrolytic capacitors, the diodes, and the transistors, taking
       | care to observe proper polarity and basing. Mount the transistors
       | close to the board's surface...
       | 
       | [0] https://archive.org/details/197501PopularElectronics
        
         | hvs wrote:
         | Until microcomputer boom of the 70's and 80's there was the
         | calculator boom of the early 70's. The availability of the
         | microprocessor made small calculators widely available for the
         | first time and they were very popular among the type of people
         | that probably would've read Hacker News had it existed.
        
         | Sharlin wrote:
         | What caught my eye was the headline about CCDs as successors to
         | video camera tubes. Charge-coupled devices being, of course,
         | the sensor technology now used by essentially all of the
         | billions of digital cameras on the planet.
        
           | MBCook wrote:
           | Hasn't basically everyone switch from CCD to CMOS sensors
           | these days?
           | 
           | I don't know the technical difference other than what each
           | stands for.
        
       | danbruc wrote:
       | Cost the equivalent of $2359 back then, right now you can get a
       | few on eBay for around $5000. Or you can get a mini replica kit
       | for $150. [1]
       | 
       | [1] https://altairmini.com/en/home
        
         | twoodfin wrote:
         | Lest you worry you (or your parents) should have stashed away a
         | few Altairs, that $397 in a tax-advantaged retirement account
         | investing in the S&P 500 would be worth more than $70k today.
        
       | NoSalt wrote:
       | Wow ... the man who invented it, Ed Roberts, had quite the life:
       | * Air Force enlisted            * Air Force comissioned
       | * Electrical Engineer            * Computer inventor            *
       | "Gentleman" farmer            * Medical doctor
       | 
       | https://en.wikipedia.org/wiki/Ed_Roberts_(computer_engineer)
        
         | pipes wrote:
         | Bill Gates goes into this in his autobiography, source code.
         | Paints a very positive picture of him.
        
       | embedded_hiker wrote:
       | My school library ( 6th - 8th grades ) had this magazine, and
       | they had a 9-week class on programming in BASIC using a 110 bps
       | teletype connected to an HP2000C that was shared by several
       | school districts. That was my start in all of this. I didn't get
       | my own computer until the C64 price dropped to $200 in 1983.
        
       | CarVac wrote:
       | My dad has an IMSAI 8080 which is a neat piece of hardware. It
       | still works, though a few LEDs failed.
       | 
       | Unfortunately for him, in university one of his professors
       | advised him not to go into computers for a career...
        
         | kabdib wrote:
         | in 1977 or so my dad (a college professor) advised me not to go
         | into computers
         | 
         | a couple of decades later (i hadn't listened, and had been
         | working for high-tech Silly Valley for quite a while) he
         | apologized :-)
        
       | jodydonetti wrote:
       | Olivetti P101 (1965)
       | 
       | https://www.fondazioneadrianolivetti.it/en/p101-cecam/
        
         | pan69 wrote:
         | It's an interesting one. Some people call it a Personal
         | Computer others call it a calculator. However you classify it,
         | it was certainly a interesting and important stepping stone and
         | it's a shame that a lot of European innovations are often
         | forgotten or skimmed over:
         | 
         | https://en.wikipedia.org/wiki/Programma_101
        
       | mrcwinn wrote:
       | For those interested in Ed Roberts, refer to Robert Cringely's
       | "Triumph of the Nerds," in particular Volume 1.
        
       | downut wrote:
       | I cannot find it but I think for about a decade the music cart
       | rotation at WREK was powered by a student built automation system
       | on an Altair. Don't remember any faults in the years I was around
       | it.
       | 
       | (I was a music director at WREK in the early '80s)
        
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