IBM Selectric Typewriter & its digital to analogue converter

[JoaoKost]

fringe



[kahvac]

I still remember my first Selectric. Nothing like it ever existed before. It was very advanced for it's time. Thanks for taking the time to explain this incredible machine !

[jix177]

Very well explained! Thanks.



[massacreman3000]

This kind of things makes me wonder about all amazing things of yesteryear.

Even mechanical typewriters are awesome to watch in action.

[ww2315]

Tilting and rotating printheads go back as far as the late 1800's. IBM's machine was not a new concept..

[BraunMannn]

@ww2315 Dear vvvv., It sounds like you have been to the Science Museum in London. They have lots of thing's development on display. Including a display of the CD and its ancient (AT&T) Bell systems customer billing punch card machine; and even back further; (all on the third floor) . Heaps of things to see, better than 'being old' and having seen it all first hand; or You-Tube, even. . . Cheers. from, del-boy.

[appleip]

i got a Selectric composer that is a amazing peace of equipment

[Xerox6085I]

The funny thing is, the IBM selectric did not work when it went into production and it was "fixed: by field service technicians...

[HB45175]

Anyone else think that typed letters look nicer than printed ones? I think it's because a typed letter isn't flat like a printed one, you can feel a bit of texture. And printed letters feel very artificial and computerlike.

[jjovereats]

Should I create a non-electric version of this?

[akkudakkupl]

What you could do - a episode about high precision machines used to produce lower precision machines, and how were the high precision machines made in the first place :-)

[suresh1957]

Great video, lucid explanation of an icon ! I had always wanted to own a Selectric but had to settle for a Canon AP100 instead. The latter wheels used daisywheels instead of the spheres that the Selectrics used, an advancement perhaps . Nonetheless, the Selectric looked solid and better engineered than the Canon

Suresh

Strasbourg, France

[Vaughnlesterinoz]

I'd love the chance to type on different kinds of typewriters oneday and get some hands on time with them. I've recently become obsessed with keyboards and have started collecting mechanical keyboards. (I already have enough rubber dome ones and don't need to buy any more of them.) I really enjoy typing on my Ducky 9008 keyboard with Cherry MX Blue switches. The switches sound and feel very good when typing, however I still want to try Buckling spring switches.

[sayrith]

the college I go to has two of these things in the library. Idk if they still work though

[Savannahsens3]

wish they'd chosen a better layout than qwerty

[PSNDonutDude]

@Savannahsens3 Would you like to know, why they designed the Qwerty keyboard?

[Savannahsens3]

@PSNDonutDude i believe the qwerty layout was originally intended to stop key jams on type writers.

[PSNDonutDude]

@Savannahsens3 That is correct, due to people knowing how to type too fast the subsequently made the typewriter jam, therefore they made the Qwerty keyboard to slow people down. This of course did not slow people down, and the problems continued.

[Savannahsens3]

@PSNDonutDude as I understand it, it wasn't necessarily to slow them down but rather to space the commonly used key sequences out so that you hardly ever hit two adjacent keys, obviously this does have the effect of slowing them down. The fact is that qwerty is far from optimal, layouts such as dvorak, are designed to lessen finger motion and increase typing rate... in fact a plain old abcde layout is better than qwerty. That said I'm still using a qwerty keyboard.

[Vlakpage]

@Savannahsens3 Yes, qwerty has been there for 140 years, it might be called optimal for some period of time but now it's definitely not. It really amazes me that people have to use such ancient and complicated input method in 21st century, there was hardly any development since the last century. On the other side, the output, screen/monitor, are still evolving fast, as of now with high density 3D capable images. Yet we still try to hit over 100 letter and symbol keys one by one...

[DanTromedlov]

I have one of these, an IBM selectric II.

[sp1ink]

really fantastic please keep making these videos cause i will watch all of em!

[pdblouin33]

I don't understand how the movement of the ball is "Analog" - in my experience I've only heard of A to D conversion (the more bits, the smaller the increments can be between one digital signal and the next-highest position).

But the movement of the ball is not "continuous" i.e. analog, is it?

[ACA332]

Amazing piece of engineering. I feel even worse now having seen one in a dumpster recently, where I also found and saved a digital camera and pair of binoculars.

[timerider4]

So why are the letters laid out the way they are on the ball?

[gskaplan]

This is such a GREAT video. I am also a Selectric fan and have the service manuals that describe this. I remember first reading this section and thinking how brilliant the design was.

I am a collector of IBM Composers, a machine based on the Selectric.

[artifactingreality]

I want to see it hooked to a computer.

[jamie1707]

Wish I had a nickle for each hour I spent typing away on those machines. When they first came out, I was 'programing' and using IBM series 407 tabulators and all the different types of machines that hooked up with them, along with a IBM 1401 system. The arrival of the IBM Selectric was a clue that those venerable machines were finally on the way out. Fun fact: the Selectrics were used for a time to train key punch operators, there was a special type element for just that purpose.

[cyanidesan]

you guys are really awesome.. just a few months ago i learned about the khanacademy videos and now i can watch all this for free too! thanks for keeping knowledge free. i learn more from the internet everyday that i ever did when i was in school!

[liberty2001]

The shift mechanism works by moving the right hand rotate tape pulley out, which cause the element to rotate 180.

A truly amazing machine.

[Meddlmoe]

How do the positions of 3 tabs encode 22 posistions?

[engineerguyvideo]

@Meddlmoe . I should have highlighted one more of those levers in blue. The far right one hooked to the cable and so transfers the "pulls", but the lever second from the right is part of the whiffletree tabs. That would give 2x2x2x2 which is 16 and is more than enough for 11 rows. The shift lever is not shown in the drawing. Note that is is a TOTAL of 22 rows ... 11 on each side. So if the ball is set for lower case you need 11 positions; if it is in upper case 11 positions. Does this help?

[Meddlmoe]

@engineerguyvideo Thank you, it did help.

[SpecialtyLEDSonline]

@engineerguyvideo Fascinating! Hard to believe that this thing even works, and works as well as it does!

One thing that has ALWAYS fascinated me is how we design and machine these small parts and devices to the exact level of precision necessary for these devices to work - repeatedly.

Have you ever considered making a "measurements" engineering video? I would it! I know today that smaller measurements are made possible by using lasers and sensors, but what were the standards for back then?

[engineerguyvideo]

@SpecialtyLEDSonline Good suggestions. Let me think about this. Year ago I recall someone saying to me that whenever you wanted to make a measurement precise you converted "it" to frequency ...... 

[scooler]

@SpecialtyLEDSonline Ah yes, all about Metrology. I'd love to see a special on Coordinate-measuring machines. They are rather incredible devices.

[SpecialtyLEDSonline]

@scooler I know, right!?  Ever since my engineering teachers mentioned the marvel of measurements, accuracy, and how to achieve specific error tolerances - I've always been curious how they accomplish these standards of measurements on a nano-scale level.

[SpecialtyLEDSonline]

@Meddlmoe - Great question! I hadn't thought of that! 3 bits would not give enough combinations for the typewriter to access and output all of the necessary symbols printed on the ball. Very complicated, indeed, and using the least amount of parts necessary to accommodate the device. Can you imagine the amount of trial and error there must have been when the first designs and prototypes came out? The level of precise measurement and mechanical fine tuning is a whole different story, too!

[zebfeldman]

The complexity of the selectric is truly remarkable as is how few folks understand or understood the elegance of the design. Thank you Bill for explaining how the type element works as well as the analog to digital component. Perhaps you can discuss how the correcting mechanism worked on the old models prior to correction tape.

[felipeceglia]

what is the background music?

[engineerguyvideo]

@felipeceglia It is music that we purchased for this ... it designed to be used like the segues and background music in desperate housewives, six feet under, etc

[dragonheadthing]

Neat video! I have wondered for years how the ball kind of typewriters work.

[1944GPW]

Just follewed through to this from an article on Hackaday. It brought back memories of our Selectric back in the 70s, and what an incredible piece of engineering it was. My dad worked for IBM and we also had a scrapped Selectric I/O Writer which had a bunch of tilt/rotate solenoids underneath the main Selectric chassis. We had intended to get it working with our 'home microcomputer' back in 1979 (a Fairchild F-8 3850 kit) but never did get far with the interface logic unfortunately.

[pornstar7g]

nice video...

[frac]

I remember the security scandal of the IBM Selectric's day was that the ribbon held a clear and very readable copy (in reverse) of everything the typewriter had typed since the ribbon was replaced.

[SpooderW]

Fantastic as usual!

[engineerguyvideo]

@SpooderW Thank for you for nice comments ... another one comes on Tues AM .... this type a very, very simple device compared to Selectric, but not the less extremely impressive to my engineer's eye!

[vk2zay]

I have always wondered how golfball printers worked. That is far more wonderful than I had imagined. Very ingenious mechanism!

[TheQuiltington]

Interesting - but what happened to the fun part?

[engineerguyvideo]

@TheQuiltington That's an interesting question. I assume you are referring to the irreverence of the first series of videos (stealing photocopiers & the like) ... this is still an experiment as I learn about this medium (I had done a lot of radio in the past) ... we decided in this set to use our time to explain more, and to use our effort to film in a way that revealed more about the objects & their engineering. Is this the correct approach: We'll see ....

[mikecane2008]

Ah, that lovely keyboard. Still nothing like it. And there was nothing like typing away all night -- rat-a-tat-tat -- and driving the neighbors downstairs into advanced sleep deprivation.

[engineerguyvideo]

@mikecane2008 For someone of my age that sound is very evocative. Nick came up with the idea of starting this next set of videos with something visceral: The sound or motion of the object. For this one I put that microphone just a few inches away!

[morto360]

Funny thing is.. when you watch to 30 years old technology from todays point of view.. it looks amazing and brilliant in some ways.

I wonder if the people in the future, 30 years from now on will think the same about todays technology, since it looks like a lot garbage to me today.

Not because its bad... its more like, "use it 6 month, then trow it away and buy a new" type of garbage.

[engineerguyvideo]

@morto360 It IS brilliant! But you make a great point. In my classes I often have to reach back in technology to show mechanical things, which are easier to understand than electronic ones. For example, I STILL discuss the VCR ... (alert for those under 40: This was an ancient device to play back television using magnetic tape) ... because it is wonderfully mechanical. The DVD player, not so much ....

[FyberOptic]

Excellent video. Due to the number of bits, up to 32 positions would technically be possible, but that doesn't explain the case of the letters. Do the shift and caps-lock keys control which hemisphere the ball is held in in real-time? Or does the extra half-rotation only happen after you press a letter to be typed?

[engineerguyvideo]

@FyberOptic Excellent questions. IBM put 88 characters on the type element. There are 4 row and 11 columns on each side -- 44 lower case on one side and 44 uppercase on the other. The shift keys flips the ball back and forth between the hemisphere -- that's way I said 22 columns (I used both sides together). When you press the shift the ball rotates, and then the tilt and rotation (identical for each side) happens. Will see if I can post video to the engineerguy facebook page. of the shift ...

[engineerguyvideo]

@FyberOptic I dug up a clip of the shift rotation (it was on the cutting room floor!) and put it up on engineerguy facebook page - available to all, no need to friend - you can get there from facebook (obviously) but there is also a link at the top of every page at my web site - which YouTube won't let me put here!

[tremer88]

this is like converting my fwd car to rwd. i love it

[urnot4me69]

Nice explanation and demonstration.

[engineerguyvideo]

@sparkybaz77 Thx. Don't know how old you are, but as I mention in the opening my parent had one ... and I was fascinated with it. In 1973 or so there were no computers, video games, etc in the house. So something like this was amazing to a 11 or 12 year old kid. Just amazing. And the whole thing is ELECTRO-MECHANICAL, not electronic ... just an electric motor driving a shaft.