Tangentially related: is there a history covering IBM's development of microcomputers? It is clear that the traditional story of the development of the IBM PC leaves out many important details. There the 5100/5110/5120, which goes back to the mid-1970's and reflects the stereotype of IBM. There is also the System/23 DataMaster, where the hardware seems to be the basis of the IBM PC. This seems to go against the traditional story that the IBM PC was some sort of renegade project. (If anything, they appear to be companion projects. The main difference being the DataMaster's focus upon IBM firmware/software.)
The IBM Datamaster is an interesting system, but it was doomed. It had an 8-bit Intel 8085 processor, cost $9000, and came out in July 1981. The IBM PC had a 16-bit 8088 processor, cost $1565, and came out a month later. So there was no reason to buy a Datamaster
There's a good description of Datamaster in "A Personal History of the IBM PC" by Dave Bradley (one of the PC's designers). Unfortunately, it's paywalled.[1]
It did use a screen font closer to the 3270 series. That is a big pro ;-)
IBM also was studying home computers, and was talking to Atari. There are other gorgeous design studies in “ Delete - a Design History of Computer Vaporware”, a lovely book. I want to 3D print half of those designs.
Man. I love the design of old terminals, computers, and such.
I am, also, extremely glad that these form factors were abandoned. Having an old terminal, it is possibly the least ergonomic machine I have ever used.
One theory I saw argued the punch card size was the reason for 80x24. But why were punch cards that size? They were designed off of the cards used for the census. Why were the census cards that size? Because they were modeled after the dollar bill size.
I do love thought experiments like this but do believe they’re insatiably unresolvable.
And the reason they were modeled after the dollar bill size is because there were already many types of systems for storing and organizing them. That came in handy for the census.
The old BBC Connections series has a segment with James Burke using the old census tabulators.
That one also turned out a myth :) CD size was determined by Cassette tape dimensions (diagonal, human can still hold one in one hand) and that combined with conservative pits/lands/track pitch choice drove the play time.
thus CD runtime was derived from something "what we had at the time".
The story as told may be inaccurate but it wasn’t simply ‘what we had at the time’ either.
The 74 minute length resulted from Sony rejecting the Philips 60 minute 11.5cm diameter “Pinkeltje” disc size in favor of a 12cm diameter.
It’s quite possible that Sony’s Norio Ohga simply argued that the 9th symphony or various operas fitting would be enough of an advantage for the slight size increase without meaningfully decreasing portability.
Meanwhile the LP crowd was flipping sides like it was Ultima VIII (slight exaggeration). Why would it be critical for a new format to do away with multi-disc releases if the customer base has already grown accustomed to them?
The symphony story might be a legend, but it's pretty well known that the original design was somewhere in 10-11cm range, but this was eventually increased to 12 cm.
The "diagonal cassette size" seems extremely far-fetched - first, who cares about this? If you are worried about boxes, shelves etc.. you want horizontal size, which 10 cm. And you are worried about holding in hand, 12cm is not very convenient for the smaller hands, a smaller size would be better.
When respectfully handling them out of the box, I always stuck my index finger in the central hole and the thumb on the border. I have large hands but I rarely held them by the borders.
Fascinating article, I really like knowing where the old standards came from.
But I am extremely curious the first picture in the "The IBM 2260 video display terminal" section. All the other pictures show the typical extremely round CRT of the era, but that one is the characteristic cylindrical tube of Trinitrons, a technology released several years later. I am trying to find some information about it to no avail.
The manual for the IBM 2260 describes the CRT in detail but I don't think it has the information you want. My guess is that if you're IBM, you can get the CRT in whatever shape you want.
I am trying to find more information to no avail. Actually the only picture of an IBM terminal with a cylindrical tube is the one in your article, there is nothing else on the entire Internet. I will keep investigating.
Oh, I see the difference now. In the photo of the IBM 2260 terminal that I used, the bezel is rectangular and flat. In every other photo of the 226, the bezel is sunken and the screen is oval-shaped. I'll ask around and see if I can find out why. Maybe the photo that I used is a later version with a better CRT?
Deeply fascinated by these historical threads. It is precisely the various design choices made throughout history that have shaped the computer systems we use today.
You know, this is funny because QBasic did not use EDIT.COM. Instead, QBasic was the editor and EDIT.COM was a simple program that called "QBASIC /EDIT" :-)
The linage can be traced back to Basile Bouchon's paper tape invention in 1725. The article doesn't mention the role of punched cards in The Holocaust, though, which my blog post goes into:
The IBM Datamaster is an interesting system, but it was doomed. It had an 8-bit Intel 8085 processor, cost $9000, and came out in July 1981. The IBM PC had a 16-bit 8088 processor, cost $1565, and came out a month later. So there was no reason to buy a Datamaster
There's a good description of Datamaster in "A Personal History of the IBM PC" by Dave Bradley (one of the PC's designers). Unfortunately, it's paywalled.[1]
[1] https://doi.ieeecomputersociety.org/10.1109/MC.2011.163
You know you want it.
> So there was no reason to buy a Datamaster
It did use a screen font closer to the 3270 series. That is a big pro ;-)
IBM also was studying home computers, and was talking to Atari. There are other gorgeous design studies in “ Delete - a Design History of Computer Vaporware”, a lovely book. I want to 3D print half of those designs.
And thank you for all of your articles over the years. They border so close to applied physics they are fascinating reads.
[1] https://www.righto.com/2018/01/xerox-alto-zero-day-cracking-...
I am, also, extremely glad that these form factors were abandoned. Having an old terminal, it is possibly the least ergonomic machine I have ever used.
https://design.tel/olivetti-tvc-250/
Though I’d probably go with an IBM 3278 or 3290 for practicality.
> To avoid these astronomical prices, some computers used the cheaper alternative of shift register memory.
Might be a direction for 2026 too?
I do love thought experiments like this but do believe they’re insatiably unresolvable.
The old BBC Connections series has a segment with James Burke using the old census tabulators.
https://www.youtube.com/watch?v=z6yL0_sDnX0&t=2640s
Something related to the width of a two-horse Roman carriage… Not sure ;-)
thus CD runtime was derived from something "what we had at the time".
The 74 minute length resulted from Sony rejecting the Philips 60 minute 11.5cm diameter “Pinkeltje” disc size in favor of a 12cm diameter.
It’s quite possible that Sony’s Norio Ohga simply argued that the 9th symphony or various operas fitting would be enough of an advantage for the slight size increase without meaningfully decreasing portability.
The symphony story might be a legend, but it's pretty well known that the original design was somewhere in 10-11cm range, but this was eventually increased to 12 cm.
The "diagonal cassette size" seems extremely far-fetched - first, who cares about this? If you are worried about boxes, shelves etc.. you want horizontal size, which 10 cm. And you are worried about holding in hand, 12cm is not very convenient for the smaller hands, a smaller size would be better.
But I am extremely curious the first picture in the "The IBM 2260 video display terminal" section. All the other pictures show the typical extremely round CRT of the era, but that one is the characteristic cylindrical tube of Trinitrons, a technology released several years later. I am trying to find some information about it to no avail.
[1] https://www.bitsavers.org/pdf/ibm/2260/Y27-2046-3_2260_2848_...
I am trying to find more information to no avail. Actually the only picture of an IBM terminal with a cylindrical tube is the one in your article, there is nothing else on the entire Internet. I will keep investigating.
That’s also a very large screen compared to how much text it’s displaying. The 2260 was a very odd contraption.
https://en.wikipedia.org/wiki/IBM_BASIC#/media/File%3AIBM_Ca... (IBM BASIC screenshot)
https://en.wikipedia.org/wiki/MS-DOS_Editor#/media/File%3AMS...
I was surprised by how claustrophobic it felt to only see 21 lines of code in e.g. Turbo Pascal 7.0. Still didn’t like the squashed 80x43 mode.
https://winworldpc.com/screenshot/c38a28c3-84c3-ba28-1011-c3...
Then I remembered how larger displays and xterm felt like such a liberation a few years later.
I always encourage my fellow Python developers to stick to 80 columns for readability.
https://dave.autonoma.ca/blog/2019/06/06/web-of-knowledge/