5 ms·

Cool I always thought the first PCs were like the TRS or Commodore 64 computers.

rbanffy 1y ago
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 1y ago
  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 1y ago
    The people I know who put together Altairs in 1975 used ASR-33 teletypes as terminals to run BASIC.
    - TheOtherHobbes 1y ago
      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 1y ago
    A TV output means you need to create (and have memory dedicated to) the video. A serial port is much simpler.
    - rbanffy 1y ago
      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 1y ago
  Did it not have a serial port? Would have assumed that connecting it to a terminal or teletype was the standard thing.
  - whartung 1y ago
    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 1y ago
      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 1y ago
    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 1y ago
      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.
- dowager_dan99 1y ago
  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 1y ago
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).
- rbanffy 1y ago
  If we draw the line at “home computer” we can give Honeywell the crown, even though I doubt even a single one was actually used as a “kitchen computer”
chasil 1y ago
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 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 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 https://en.m.wikipedia.org/wiki/KIM-1
mixmastamyk 1y ago
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 1y ago
"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.

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 1y ago
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 1y ago
  The people I know who put together Altairs in 1975 used ASR-33 teletypes as terminals to run BASIC.
  - TheOtherHobbes 1y ago
    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 1y ago
  A TV output means you need to create (and have memory dedicated to) the video. A serial port is much simpler.
  - rbanffy 1y ago
    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 1y ago
Did it not have a serial port? Would have assumed that connecting it to a terminal or teletype was the standard thing.
- whartung 1y ago
  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 1y ago
    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 1y ago
  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 1y ago
    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.
dowager_dan99 1y ago
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 1y ago

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).

rbanffy 1y ago
If we draw the line at “home computer” we can give Honeywell the crown, even though I doubt even a single one was actually used as a “kitchen computer”

chasil 1y ago

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 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 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 https://en.m.wikipedia.org/wiki/KIM-1

mixmastamyk 1y ago

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 1y ago

"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.