The term "1977 trinity" has been used, here on Retrocomputing SE and elsewhere, to refer to a set of three computers that started shipping in mid- to late-1977: the Apple II, the TRS-80 Model I and the Commodore PET 2001.

This kind of term does not seem to have been unusual; the Japanese had an almost identical one (allowing for cultural differences) by the early '80s: 「御三家」 (gosanke), referring to their trinity of the Hitachi Basic Master, Sharp MZ-80K and NEC PC-8001, released from late 1978 through mid-1979. (With the rise of 16-bit machines this term was later amended to 「8ビット御三家」, hachi-bitto gosanke.)

Wikipedia mentions the "1977 trinity" in several places, but their reference is to the web version of a BYTE magazine article from almost twenty years later: "Most Important Companies" (BYTE Vol 20 No 9, Sept. 1995, p.99). It says, under "Commodore International" (p.100),

But along with Apple and Tandy, it was one of the 1977 Trinity: the three companies who brought out ready-to-run PCs.

But I can't find any references to the term in contemporary issues of BYTE. Carl Helmers' column "Reflections on Entry into Our Third Year" (BYTE Vol 2 No 9, Sept. 1977, p.6) says,

The "appliance" computer, a complete system presented in an assembled and tested package is on the threshold of its ultimate dominance in the general purpose personal computer field: from the high end, moving down in price, we find products like the Apple-II and the Commodore PET 2001 machines....

The last half of 1977 represents the entry of several relatively large concerns into the marketplace, in the form of Heathkit this summer and Commodore soon to follow. Rumors have it that companies ranging from Atari...to Radio Shack and Texas Instruments are in the process of developing general purpose systems appropriate for personal computing uses.

No other computer, much less "trinity," is mentioned in BYTE's coverage of the PET announcement, "Commodore's New PET Computer" (BYTE Vol 2 No 10, Oct. 1977, p.50), or the TRS-80 announcement, "The TRS-80: Radio Shack's New Entry" (BYTE Vol 2 No 11, Nov. 1977, p.446).

A quick scan of the tables of contents of BYTE from September to December of that year shows nothing else that looks like it would mention this "trinity," either.

So was this term really first coined in 1995, or were people using it earlier?

  • 3
    I wouldn't wonder if it has been coined before the late 1980s - and even less widely used before the mid-90s. After all, it's a retrospect title. Them being the most successful wasn't clear until may years after their introduction. Just look at the contemporary magazines giving other systems way more publicity than either of the three. Of the three only Tandy was of (some) reputation. So while the question in itself isn't wrong and highlights contemporary vs. retrospect view, it is of the kind that can't have a definite answer - one the Stackexchange format is made for.
    – Raffzahn
    Commented Sep 18, 2019 at 11:29
  • 2
    And I disagree that it can't have a definite answer: just find publications that used it and cite them. That said, if you feel the question would be better worded as "what were the earliest uses" of the term, or "was it used before 1995," feel free to edit the question title.
    – cjs
    Commented Sep 18, 2019 at 11:38
  • 3
    A search of the Byte archive CD shows that the term wasn’t used there between January 1990 and the September 1995 issue quoted above. Commented Sep 18, 2019 at 12:25
  • 7
    Terms like that are most typically only formed in retrospective - For a contemporary author, it was really impossible to tell that the three would have that long-lasting significance (and not only two of them, or a new, fourth one). Also note, the "trinity" was only valid on the US market. Europe or Japan were different, with Tandy's footprint, at least in continental Europe, close to zero and none at all in Japan.
    – tofro
    Commented Sep 18, 2019 at 13:14
  • 5
    @Raffzahn I speak as somebody who remembers computers in the late 70's and early 80's because I was there. My parents bought a Pet (in 1980, I think). The Apple, Pet and TRS-80 definitely were considered the "big three" at the time. I have to admit t that I have never heard the term "Trinity" applied to them before.
    – JeremyP
    Commented Sep 19, 2019 at 9:27

3 Answers 3


The phrase "1977 Trinity" was not in common usage before 1995. It's a bit challenging to prove a negative, but if given how information was shared in those times, I'd expect to find that more than one magazine would have used it. All the references I can find come from publications after 1995, and all that refer to it say, "later referred to in Byte Magazine as..."

I think the term was invented (and therefore first used) in the Byte retrospective article in 1995.

  • It would be handy if you could tell us what you searched and give the references you did find.
    – cjs
    Commented Oct 18, 2022 at 6:19

Back in '77 no sane person would have claimed that the Apple and Commodore computers were part of a "trinity" of computers for use at "home". As a young person that loved technology I went and looked at all three machines as soon as they became available. The Apple machine was gorgeous but very expensive. In '78 they offered the machine in bundles and the bundle for students (32K with floppy disk drive and printer) cost as much as a brand new old stock base model Firebird. They were literally the same price so almost no one had an Apple ][ in their home. The P.E.T. cost about half that but still much too expensive for home use. The TRS-80 Micro Computer System was about half the cost of the P.E.T. and was the first machine to sell more than 100k units (Apple sold less than 8k units in the first two years). The MCSs were used in peoples' homes but were still quire rare. It wasn't until Commodore introduced the VIC-20 a few years later that computers began selling in the millions and became a common sight in homes. [Some people did not consider the VIC to be a "real" computer so in that case the C64 was the first computer to sell more than a million copies. No matter how you look at it Commodore was the first company to sell more than a million computers.] Comparing the corporate hype to reality It is clear that the "fake news" did not just start recently but has been going on for decades.

  • 1
    1. This does not address in any way the question about first use of the term. 2. Price or whether you consider something a "home" computer is not relevant to this. 3. Sales figures are not relevant to this, nor are the Trinity any less "appliance computers" for having higher or lower sales figures. 4. Issue you seem to have with "corporate hype" and "fake news" over early appliance microcomputers ...I can't even tell what it is, an imaginary grievance, I think?
    – cjs
    Commented Oct 16, 2022 at 23:24
  • And not really relevant, given how off-topic this answer is anyway, but comparing an Apple II with many expensive accessories (drives and printer) to a PET or TRS-80 without these does not give a sense of relative prices, and the Disk II wasn't even available when the Apple II was first released. All three systems were first released in 4K memory configurations with cassette tape used for storage and the Apple II, while still more expensive in this configuration, also had features the others did not (such as colour graphics, sound, expansion slots and a switching PSU).
    – cjs
    Commented Oct 16, 2022 at 23:27
  • 1
    @cjs eliminating a lower bound is definitely quite useful.
    – RonJohn
    Commented Oct 17, 2022 at 6:28
  • 1
    This does not "eliminate a lower bound." The 5% of the post that even tangentially addresses the original question (though it seems more concerned about the term "home," a term never used in my question or those it quotes) is entirely unsubstantiated opinion. It's beyond me how this is getting so many votes.
    – cjs
    Commented Oct 18, 2022 at 0:10
  • 1
    @Tommy Right, and the Apple II was the most expensive of the three. The TRS-80 with a display and cassette recorder was $599 ($2,940 today) in the first RS computer catalogue (page 4; pages 1 and 5 both mention "home" uses of the computer); this is the same price as the stereo system on the cover of the RS catalogue from the same year. In 1977 all base model Pontiac Firebirds cost over $4000.
    – cjs
    Commented Oct 18, 2022 at 6:17

The book Personal Computers: What They are and How to Use Them by Byron G. Wels (ISBN 9780136578666) published in 1978 covered these computers exclusively so a trinity existed in concept if not in name. This book also recommended repairing a broken motherboard with glue and soldering over the traces.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .