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.
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" :-)
I always assumed the reason the PC had an 80x25 display was to allow for emulating the 3270 (80x24 for content and then an extra line at the bottom for the status information) so it's interesting to see that wasn't the case.
> Also, 3270 emulation was not a requirement or goal for the IBM PC, and didn't lead to the 25th line. I would much prefer to have a tidy story where the 3270 led to the PC's display, but unfortunately that's not the case. I talked to two of the original IBM PC engineers to check on this. The said the IBM PC team felt absolutely no need to be compatible with other IBM products. In particular, several features of the PC made 3270 compatibility harder: the use of ASCII instead of EBCDIC, little-endian words, and 10 function keys instead of 12.
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?
For classical music it's a problem because the long track lengths mean that you'll have to flip the record over in the middle of a piece. This was enough of an annoyance that one French label in the 70s created special records just for classical music with extra tightly packed grooves that could hold close to an hour on each side (https://www.discogs.com/label/184887-Trimicron). The downside of this is that the maximum recording volume is significantly reduced so there's a lot more background noise than on a normal record.
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.
If anything, I'd have guessed that the size of an 8-track in a car stereo was probably a larger influence on potential form factors for CD audio. Since car stereos were at least somewhat normalized in the early 80's. Not speaking to an adapter, just in terms of what would "fit" in a typical stereo hole in a car.
That said, I doubt that's the reality either... it's probably a number of factors. I am slightly surprised that a USB based read-only media format standard for players hasn't materialized, though it seems that online/rental models are what the industry really wants.
Source is Dr. Kees A. Schouhamer Immink. Philips’ principal engineer in the joint efforts of Sony and Philips to develop the Compact Disc (CD) https://www.turing-machines.com/pdf/cdstory.htm:
>The disk diameter is a very basic parameter, because it relates to playing time. All parameters then have to be traded off to optimise playing time and reliability. The decision was made by the top brass of Philips. 'Compact Cassette was a great success', they said, 'we don't think CD should be much larger'.
>As it was, we made CD 0.5 cm larger yielding 12 cm. (There were all sorts of stories about it having something to do with the length of Beethoven's 9th Symphony and so on, but you should not believe them.)
> The 8-14 bit channel code was agreed and all the specifications between them led to a playing time of 75 minutes.
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?
No mentioned are the PC terminal apps from BBS era dialup connections that tended to use one of the 80x25 lines as a status bar, leaving 24 lines for the remote display... not to mention avoiding or embracing wrap issues that sometimes left you from using column 80 reliably either.
It's kind of nice to see a lot of resurgence in terminal technologies and remote terminal apps these days... I think AI is letting a lot of people that have been nostalgic pick up projects that would have been too daunting otherwise. Myself included.
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.
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:
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