Essentially, my question is there in the title.

Tower cases are commonplace these days, and probably are the "default" form factor for personal computers (or at least were, before they were surpassed by laptops).

However, the original IBM PC, the PCJr, the Mac II and the Amiga 2000 were all desktops.

At some point - I guess during the 386 era - towers started to gain traction. They eventually surpassed desktops, I'd say sometime in the 90s, with IBM releasing the Aptiva tower crowning the form factor's popularity.


  • who was the first to come up with the tower form factor?
  • which models were key in popularizing it and when?
  • 2
    NCR actually trademarked the name "Tower" when they introduced their Tower 16/32 computer in 1982. That might have actually popularized the term, though I don't think it was the first computer in the tower style. The DEC Rainbow 100 was also available in a tower configuration in 1982. – Ross Ridge Sep 3 '17 at 20:40
  • 1
    There's actually not much of a problem in placing a "traditional" desktop computer narrow side down under the table - Voilá, tower. I used to have an IBM AT at work we had to set up under the desk like that for space restrictions long before the first "real towers" entered the market. – tofro Sep 4 '17 at 11:05
  • 1
    Seconding @tofro, I recall seeing the same done with original IBM PCs (the two-floppy version), for the same reason. – Jeff Zeitlin Sep 4 '17 at 13:51
  • I guess the 128K Mac wouldn't count as it's not a tower. But, it was the first vertical PC I'm aware of. And it could be expanded...SOMEWHAT. lol. – cbmeeks Sep 18 '17 at 12:32
  • @tofro I seem to remember at least one early PC clone even had a "name plate" that could be rotated through 90 degrees so it could be "the right way up" in either configuration. – TripeHound Sep 19 '17 at 14:13

The tower form factor was well known in the 1980's, even IBM was using it at that time (the IBM RT 6150 was available in both desktop and tower cabinets, and IBM even had a tower stand option for the PC AT 5170). And it wasn't unusual to stand a desktop cabinet on its side; this practice was common in office environments when the system unit and monitor together were too tall to fit underneath the overhead cabinet in a cubicle, or the shelf above a credenza. In such cases you would simply stand up the system unit (typically next to or under the desk), which allowed the monitor to fit underneath the shelf or cabinet.

IBM wasn't the only one doing this -- in the 1980's DEC also had systems that were available in desktop and tower configurations, notably the MicroPDP-11 (in the BA23 cabinet) and the Professional 350/380 line. (ref: http://bitsavers.informatik.uni-stuttgart.de/pdf/dec/pdp11/handbooks/EB-24944-18_Micro_PDP-11_Handbook_1983-84.pdf)

  • I wish I could accept all answers, but this wins because of the PC AT 5170 mention, which I believe is more in the same class as your garden variety 2017 PC than the exotic ICL Perq and the like. – Tobia Tesan Sep 16 '17 at 8:00

The tower is neither an invention of the 90s nor was it done by IBM.

  • For example NCR sold their PC8 series in tower form factor since (at least) 1986 with 286 CPUs.
  • IBM hat the PS/2 Model 60 in 1988
  • Many companies put x86 PCs into tower cases, already with 8088 CPUs
  • Not to mention stands that where available to turn an IBM PC into a tower

I bet with some search will show a lot of other tower x86 systems from right after the IBM-PC got introduced.

  • Before the x86 PC there where several S100 cases build to be used as a tower
  • Before that, DEC put various PDPs into tower like racks ment to be placed below a desk
  • Even the mother of all desktop-GUI machines, Xerox' Dandelion series was build in tower style.
  • 1
    The tower is neither an invention of the 90s nor was it done by IBM. Mind you, I did very much not imply either statement. I did imply that towers became the default in the 90s, but my perception might be wrong. – Tobia Tesan Sep 3 '17 at 21:38
  • The PC8 is an interesting one. – Tobia Tesan Sep 3 '17 at 21:40
  • I had a 286-based PC manufactured by ICL in a full-tower form factor that was produced in 1986 according to the BIOS copyright date. They were pretty common around that time. (The machine looked like the one at the bottom in this picture, except mounted in a bracket that held it upright ... the other interesting thing about it was that was supplied with Windows 1.0 and this rather unusual OS). – Jules Sep 5 '17 at 19:35

Back in 1986, I was using an ICL Perq on a computing project when I was a student. As you can see from the photo, not only the computer, but also the monitor was in tower format.

As you can also see, the tower itself was massive by today's standards. For reference, it was wide enough for an 8 inch floppy drive to be installed horizontally.

  • The PERQ is IIRC a lineage older than the PC... – rackandboneman Sep 16 '17 at 22:27
  • @rackandboneman The question doesn't restrict the answer to being PC only. It simply askes when the tower format became popular. – JeremyP Sep 18 '17 at 9:03
  • 1
    In houses, it certainly has first become popular in the middle ages? – rackandboneman Sep 18 '17 at 10:07

PC specific, ignoring non-PC systems here.

Remembering early-90s systems, 286 machines were mostly built in the "Baby-AT" form factor. Sometimes you still saw new 286/rarely 386 builds in the full-width AT form factor, which is surprisingly huge :). 386/486 machines were a common sight in both Baby-AT and minitower/full tower form factors.

One likely reason for this trend was that technologies that allowed more than the maximum 4 (two floppy, two hdd) drives designed into the original PC and AT designs became more mainstream. The classic full width PC and AT form factors were only meant to take 5.25" type drives (3.5" were used with adapter brackets), could typically take 4 half-height drives or 2 full height. Baby-AT typically allowed 3 5.25" half height (often with only 2 externally accessible. Could be used with 1 full 1 half in some, excuse the pun, cases) and one 3.5" device. SCSI in the PC was the newest high-end trend in the early 90s, and allowed up to 7 drives, and probably catalyzed adoption of tape and CDROM devices (however, the mainstream versions of these were typically NOT the expensive SCSI type). Obviously, all these new possibilities caused problem with the desktop form factors limited in drive slots, whereas tower cases could be built to various heights with nearly limitless expansion capacities for mass storage...

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