THE IMPACT OF PRINTERS UPON CHARACTER SETS

This is the first draft of a "computer history vignette" for inclusion on the website www.bobbemer.com . It is marked up to indicate how the author would turn it into a History Channel feature.

What follows is obviously a very limited first draft. More time is needed for further research. It can be expanded to a full treatment later. But the aim is to present a piece of computer history about two seemingly different aspects, which really are not separate, but are interdependent in a most interesting way.

It is submitted because I do not find enough History Channel shows about computers, at least in ratio to their importance and present ubiquity. Computers have now had more effect upon society than wars. Wars require renewal, and rebuilding. Computers build, not rebuild.

I don't know if any TV show or documentary has shown a reference to a Web site long enough to write it down, but it may be a good idea to run an occasional strip at screen bottom where a reference is given while the story proceeds. It's done for stock market quotes and sports scores. Why not provide guides to further information on the topic(s) of the show?)

In preparation, the History Channel should have a catalog and index of where all computer artifacts are available -- footage, actual equipment, pictures, and papers. In museums, libraries, home collections, manufacturers' warehouses, and Web sites. If not complete, start quickly!



Voice

 

Video

Ask someone born after 1980 to describe a typewriter to you, and you may get nothing but a blank stare. "What's that?"

 

An individual field interview? Or a teacher asking a class and reporting the results.

Ask someone born about 1970 to describe a typewriter to you, and you might find a few in a hundred that have seen an electronic version in a computer store. The kind many people disliked because the printing lagged so much behind the actual keystroke.

 

An electronic typewriter.

Ask someone born about 1960 to describe a typewriter to you, and a few might remember seeing an IBM Selectric typewriter -- the type with the rotating ball -- in some movie or in someone's attic.

 

IBM Selectric

Ask someone born about 1950 to describe a typewriter to you, and they probably can, to some detail. Then ask them where they last saw one. You'll probably get a puzzled look and a question. "Where have they all gone?"

 

Picture of old upright non-portable. Underwood? Show the basket working.

That "Where have they all gone" is the subject of our current look into history. The change from typewriters being the basic equipment of a secretary, newspaper reporter, or novelist, in the first half of the 20th century, to their virtual disappearance is one of the great stories of technology.

 

Lots of film possibilities here, Actual typists. Maybe a roomful, in a newsroom.

People love to look at pictures on their personal computers. Which is why they're forever trying to get faster machines, for those picture are sent one tiny bit at a time, in contrast to text, where each letter or character is sent as only 8 or 16 bits, and the local computer makes the picture of the letter or number. Much faster, and we couldn't do work with just pictures, anyway. Picture books are OK for children, but it takes text to enable thinking and invention.

 

VIDEO ???

When computers first appeared, pictures were impossible, but we could print any of 48 different characters -- about 26 for the alphabet, 10 for the digits 0 through 9, a plus and minus sign, and a few other punctuation marks. This was inherited from punch cards and previous U.S. Census work.

 

A punch card with rectangular holes, punched in 48 columns. Perhaps with the graphics interpreted along the top.

When the ENIAC computer appeared, and developed into UNIVAC, it had three more, up to 51 characters.

 

UNIVAC punch card, with its round holes.

Now, less than 50 years later, computers can manipulate, show, and print about 100,000 different characters and symbols! How did this ever happen?

 

Show mixed Arabic, Kata Kana, and Roman alphabets -- on CRT screen and on paper.

And now we can manipulate, show, and print pictures and graphs. In colors. Hundreds of different colors. How did this happen?

 

Any graphic you like.

Understanding Character Sets

First, what do we mean by character sets? Loosely, it is a group of items that have pictures or symbols. In sets of alphabetic characters, the characters are the pictures assigned to each. The same with numeric digits and punctuation.

 

Show a Roman set. Perhaps on children's wooden blocks.

Don't think just of the "Roman" alphabet. In Russia the alphabet is close to Roman, considering the characters that exist, and the sounds they make. But many of the pictures in the Cyrillic alphabet are quite different. That's why you can't pronounce the words unless you know what sounds the pictures stand for.

 

Russian alphabet - a sign in Cyrillic - see "History Channel" in Cyrillic.

In Chinese the pictures are different, too. They often don't stand for sounds, but for concepts and ideas. We're told that using two symbols for "woman", with a symbol for "roof" over these, makes a symbol for "trouble". The Chinese don't go in for spelling all the time.

 

Show some general and innocuous ideographs.

And don't think just of the decimal system of numbers, with its ten different digits. The Mayans used twelve, not ten. And on the inside computers use just two -- zero and one. To work with computer digits, many programmers use sets of 8 (octal) or 16 (hexadecimal). The Roman numeral set was interesting because it didn't have a "zero". They didn't know the concept.

 

Comparative digit systems

  0000  0  0  0      
  0001  1  1  1     I
  0010  2  2  2    II
  0011  3  3  3   III
  0100  4  4  4    IV
  0101  5  5  5     V
  0110  6  6  6    VI
  0111  7  7  7   VII
  1000  8  8  8  VIII
  1001     9  9    IX
  1010    10  A     X
  1011        B    XI
  1100        C   XII
  1101        D  XIII
  1110        E   XIV
  1111        F    XV

There Are Many Fonts

A picture of a letter character can vary, just as no two pictures of you are the same. It's still a capital A if it is in thick or thin lines (bold or regular), if it has fancy curlicues or serifs (the extra little legs), if it is slanted (italic), or in script.

 

Show an example of the same text in various fonts. Show how an IBM ball typewriter might have a different ball for each font, with no changing the keytops at all.

Early computers had impact printers, and only one shape was available. Like early Fords came in any color -- as long as it was black! Many people have noted how similar the computer business is to the automobile business.

 

Maybe a picture of an early IBM 405 printer, with the old Carroll Carriage. IBM may have working footage.

Set Size

The size of the character set -- that is, how many different symbols does it have -- is pretty important to being able to print or paint with them. If you had a million different characters available, how would you choose? How could you remember the spelling? Most phonetic alphabets have from 20 to 50 characters to choose from.

 

A Roman alphabet of 26 characters. Greek at 24.

The old Morse Code had two basic symbols -- a dot and a dash. Easy to print on paper. The printing device had only to choose one or the other, then either print or not print (which was a space). You didn't even have to turn the code into pictures of letters or numbers. Someone that knew the code could read it in the raw.

 

Picture of a message, with the letters printed, too.

The recently-publicized genetic code has just four symbols. Someone picked alphabetic letters for them, but anything could have been used.

 

Something from genetics.

There are other Roman-based alphabets with other than 26 letters. Scandinavian, for example, some of which have 29. The extras look like other letters, but have added marks. These extras usually follow the "Z" when words are alphabetized, which means you'll find names that start with them near the end of the phone book. The people in the U.S. working with the new character set "ASCII" were so provincial that they were surprised when this information got to them.

 

Pages from Danish phone book

The French have extra letters, too, but they don't have equal rights with other letters. On typewriters they're made by typing the main letter, backspacing, and overtyping the accent. But you can't backspace a computer line printer.

 

Some accented French words

Of course, any characters your printer doesn't have can be spelled out. That's what they did for early teletypewriters without a period symbol. Remember the old telegram messages?

 

... I LOVE YOU STOP
   VERY MUCH STOP
   WHY QUESTIONMARK

Maybe a much longer telegram could shows more aspects of this.

We still do something like that today in HTML, the language that people use to make the pages that come up on your Internet screen, Earlier, in both typewriters and computers, we used the same quote symbol to precede and follow a quote. Published text often uses both opening and closing quote marks that are different. To get this effect, even though we enter the text with the usual keyboard of a PC, we would have to enter this strange set of text. For an IBM-type PC, that is; it's different for a MAC.

 

HyperText Markup Language

        "quoted text"


 “quoted text”

What Does This Have To Do With Computers?

Unless using a typewriter for output, accented letters increase the number of different elements for impact printers. And that's just for one alphabet, like Roman. Of course special machines for photocomposing have been around for some time. They were the natural follow-on for the old Linotype, so much used by newspapers.

 

Shot of Linotype, possibly footage in action. But surely to show the physical complexity.

How would you like to have to have one of these monsters alongside your PC? Home computing wouldn't be very affordable any more, would it? How about the repair costs?

 

Maybe a composite with a kid and his PC, the linotype taking up the whole room.

It doesn't make any difference how many different characters a computer can handle on the inside. Eventually you have to be able to see them, on a screen, or printed on paper. If you want to keep the results for later viewing, paper only.

 

V I D E O

Impact vs. Non-Impact Printing

The word "impact" is used in the sense of "force". Impact printing is striking the surface to be printed on. The impression is made by the pattern, often by knocking off carbon particles embedded in a ribbon. The cave man did it with a chisel, knocking off the patina from a piece of rock.

 

Shot of cave man chiseling a picture. Rock hammer and piece of flint. Iron age man with a real hammer and an iron pattern, banging out an "A".

Non-impact printing is getting the carbon or other material on the surface without hitting it. Today's laser printers make it adhere electrostatically. The cave man did it by painting it with a brush.

 

Shot of cave man painting a bison.

You'd have to call a printing press a LOW-impact device, painting the carbon or other powder on in a soup form called ink.

 

V I D E O

How Much Prints at One Time?

Character-at-a-time

The human hand is the original character-at-a-time printer. Of course, handwriting is all connected together, but it still forms just one character at a time.

 

Shows a hand moving and printing each character with a pen(cil).

The basket-style typewriter was character-at-a-time. Actually all typewriters are. The basket contained a hammer for each character. All hammers were bent such that, when they were driven up to the ribbon by their own key, they all hit the ribbon at one point, right in the center of the typewriter.

 

Show the bent nature of the basket elements.

This meant that the paper had to move right-to-left, or vice versa, because a mechanism to move the basket itself would be very unwieldy. That is the origin of the BEL character in ASCII, the American Standard Code for Information Interchange, now the standard language of the Internet and Web. When the typist got carried away and didn't notice that the typing was about to run off the page, the bell rang, alerting to the need to reach up to a handle and move the carriage all the way to the other end before continuing.

 

ASCII chart, with BEL, CR circled and pointered.

Then video shot of the actual typing and return process.

At first the basket hammers had just one character engraved on the end. Then someone invented the shift key, and the hammers now had two characters each -- for "lower" and "upper" case.

 

Closeup of basket in some old typewriter.

Motive power was first the force with which a human hit a key. More force, darker impression. This often gave irregular copy. When the keys were connected only electrically, the striking force was constant.

 

Can some old irregular copy be found?

Then there came type elements that rotated and moved up and down. They were so much simpler than the basket cage that one could afford to move the element itself from one end of the line to another. This meant the paper could sit in just one position, moving up or down, but not left to right.

 

V I D E O

Some teletypewriters used a drum element. It rotated to the right place as it was moving up or down to the right band of characters, after which the whole drum was banged against the ribbon.

 

Teletypewriter device -- perhaps Model 33 or 37.

Another famous type was the ball on the IBM Selectric typewriter. To make this machine, IBM had to buy certain patents from Marx Toys, which marketed a kiddie typewriter. The ball also rotated, but it didn't move up and down. It tilted to get the correct band of characters out of four, meanwhile rotating to pick one character in that band out of the 22 around it.

 

Shot of ball typewriter in action.

This machine had a great advantage over all others at the time. You could pick one of several balls and replace the old one. Now one could print with larger fonts. One could get a ball for Russian, at a cost a great deal less than a custom-made Russian typewriter. IBM certainly emphasized the "International" in its name, for the same typewriter could, by just changing to a different ball, accommodate all of the languages of the world.

 

Show several different balls, plus an actual replacement.

The idea of replaceable elements also led to a form called a Daisywriter. The daisy wheel rotated on an axis pointing directly into the platen -- the long drum that fed the paper. It too could be replaceable, even more cheaply than the ball.

 

Shot of Daisywriter, and various wheels.

The Daisywriter had another big advantage in conjunction with computers. The IBM ball was designed in their plant in Lexington, Kentucky, by engineers who would not believe that their design would be of use as a timesharing terminal. It had a capacity of only 88 different characters, in bands of 22 each. Computers worked with 128 characters, which the daisywheel could handle and the ball could not at that time. IBM had to go through some pretty big contortions later on to marry that typewriter to computers.

 

Show a wheel with a count of the characters going around the outside.

Having progressed from a split set in a typewriter basket, to a drum or ball rotating on a vertical axis, to a disk rotating on an axis perpendicular to the paper (daisy wheel), innovation then stopped for character-at-a-time printers. Printers based upon the principles of laser, stylii, and inkjet took over. Actually it's more precise to say that they went to a row of dots at a time, each row being a partial line.

 

Successive recap shots of the various methods are they are quickly mentioned.

Line-at-a-time

When computers first came into commercial use, in about 1950 or so, printers for computers were all impact-type. Here's an early type, supplied by IBM. Each column to be printed, all at once, had its own type element that contained all of the characters available to print. Here they were engraved on vertical bars. Depending upon which character was to be printed in a certain position, that bar was raised that much before the hammer struck, knocking it forward into the paper. The two characters above and below that position didn't print because the paper was wrapped around a roller.

 

Carroll carriage on the IBM 405. Show a vertical print element at various heights. IBM archives will have photos.

The hammer smacks the letter element against the ribbon, which is against the paper. So the element and the paper can't be moving by each other or you'll get nothing but smears. This is called a line-at-a-time printer. The paper stops moving while the proper print elements are lined up. The entire line is printed by all the hammers firing at once. Then the paper is moved up a line (or over a fold), and the process is repeated. This tricky process is from clever mechanical engineers.

 

Show all bars at various heights (get from IBM).

Line-at-a-time with Multiple Character Sets

Then, to print even faster, even if still with a limited number of different characters, IBM brought out their Model 1403 printer in about 1958. The print element was a chain or band, driven around capstans at either end, with vertical axes. On it were 240 character positions.

 

V I D E O

The beauty of this was that one could use different chains. Of course you couldn't just interchange them like a ball on a typewriter. The printing driver was too complex for that. But the chain could come with 5 duplicate sets of 48 characters, or 4 duplicate sets of 60 characters, or 2 duplicate sets of 120 characters. In special cases, for computers with 8-bit encodings, a single set of 240 characters.

 

V I D E O

At the other end, to print numbers only, it would be possible to get 10 sets of digits and + and -. A difference of 10:1 in how fast the paper can move. Or how many lines can be printed per minute.

 

V I D E O

Having more than one copy of the character set available is like having trains leave more often - the odds are you'll get there sooner. Or five elevators instead of just one - you've got more chances. So printing is faster with less wait for the needed characters to show up in place.

 

V I D E O

This 1403 printer was introduced at about the same time that IBM (alone) was changing the internal character size from 6 to 8 bits, and adding a lower case to the original capital letter alphabet. 6 bits per character had an upper limit of 64 characters, not enough for both upper and lower case. Which is why ASCII (which did have both upper and lower case) didn't get off the ground until people got comfy with 8-bit machines.

 

V I D E O

Page-at-a-time

A printing press hits everything at once. No movement except replacing the paper with a new sheet in a fixed position. So it is a page-at-a-time printer.

 

V I D E O

Gutenberg did page-at-a-time printing, printing many many copies from the same plate. Computers usually needed only a few copies of any page, but they need to print a lot of pages. Fast. Faster by far than the plate in a printing press can be changed.

 

V I D E O

There was just no way that impact printers could be designed to do a page in one output process. It's not so much that the page is printed all at once, but that the entire page is offloaded at one time to the printer. But before that there were other printers that used dots selectively to make the character, not a metal slug.

 

V I D E O

Laser Printer Predecessors

An article by Edward Webster in the 1963 September issue of the trade magazine Datamation gives a very good picture of the types of unusual printers available at that time.

 

From Datamation article ----

They varied in method. Some used stylii burning special paper. Some used stylii tapping against a ribbon. About all they had in common was the fact that the characters were formed by dots. Removing the restriction that the paper has to be stopped when hit (it could now keep on rolling) allowed them to operate much faster, often with continuous paper rolls. Their common characteristic was that they were used mostly by the military, which had a strong need for mixed text and pictures (maps, charts, etc.), and enough money to be able to afford such esoteric monsters.

 

Picture of dot-matrix character set from Bemer's Interface Age article on ASCII.

Laser Printers

Most everyone thinks that Hewlett-Packard developed the first working laser printer. Not so.

 

V I D E O

True -- when laser printers first became popular and affordable, a good many were of the Hewlett-Packard brand. Which caused many people to think it was their invention. In fact, the first laser printer was the brainchild of Gary Starkweather of Xerox, although where he did it is debated. Some say their Research Center at Palo Alto; some say Webster, New York.

 

V I D E O

Xerox tossed away this wonderful chance. They were in the business of making many copies of a single original. They didn't think much of making the original as well.

 

V I D E O

That was in 1969. Ten years later IBM came out with the Model 3800. Very fast, but equally expensive. In 1981 Xerox introduced the Star 8010, with the very smallest costing $16,000 plus. So they sold about 100,000 units -- obviously not to the home market.

 

Use still shots from 1963 survey article in Datamation.

Then in 1984 Hewlett-Packard produced the Laser Jet printer, at 300 dots per inch for the images, selling first for $3600, a point where the price could come down for the home, as the microcomputer Apple II had been available for seven years.

 

A shot of the original model, with its advertising.

The Effect Of Laser Printers

Lasers and other point-at-a-time printers like stylus printers removed physical limitations on set size. With a 6 x 9 matrix there are 2 power 54 different patterns available. That's over 18 thousand million million ways to form a single character.

 

V I D E O

Remember the old story of an emperor agreeing to pay off a debt by putting one grain of rice on the first square of a chessboard, then two grains on the next square, doubling for each remaining square?

 

Something to show that doubling effect.

But humans can't distinguish one character from another visually if only one dot in 54 were to be changed. And can you imagine remembering over 18 thousand million million different characters and what they mean? So these theoretical numbers are just that.

 

V I D E O

But that gives an idea why ASCII led to UNICODE when matrix printers became so common. The 65,536 different characters that are identifiable by 16 bits enable a substantial portion of the world's alphabetic characters and symbols to coexist and be used with computers.

 

Something from Windows NT usage.

That takes us up to today, where the home laser printer can cost as little as a fancy restaurant dinner in New York. Everyone with a PC has decided which to choose. Of course, if color is demanded, an inkjet printer, still on the same dot matrix principle, is the way to go. At a higher price, of course.

 

V I D E O

This also opened the way to digital cameras, when it was found that the tiny dots could be made in different sizes and intensity to give shading! Only the inventors know what is coming next!

 

V I D E O