Talk:Punched tape

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Original text[edit]

Below the line is ErikFP's original text. I did my best to salvage any useful information from it and make the article again conform to Wikipedia standards, but it is quite likely I blundered since I don't really know anything about it. Gadykozma 06:39, 15 Aug 2004 (UTC)

The first use of paper tape predates computers, it was Thomas Edison and his Stock Ticker machines also his Repeating Telegraph. These were the forerunners of what became the computer punched paper tape.

There were two standards for computer tape. The Baudot which had 5 holes and the ASCII which had 8 holes. The image above shows an 8 hole tape. Teletypes were first used in conjunction with TWX Telex (also Telegrams), they were also adopted by Ham radio RTTY operators before finding their way into service as computer terminals.

Back in the late 1960s to early 1970s, the ASR33 was a very popular teletype. It had a built in paper tape reader and tape punch (8 hole ASCII). It could read/punch tape at the blinding speed of 10 characters per second. :-) The ASR33 tape reader was purely mechanical; 8 spring loaded fingers would be thrust into the tape (one character at a time), an amazing assortment of rods and levers would sense how high the finger rose, which told it if there was a hole in the tape at that position.

The ASR33 teletype that I worked with was hooked up to an HP minicomputer. Eventually the school also purchased a High Speed Photo Tape Reader, which consisted of 8 light sensors and could read a tape at the blinding speed of 50 inches per second (a similar photo reader also came with the DEC PDP 15).

The two biggest problems with paper tape is that (1) The ASR33 punch was not very reliable. After making a copy of a tape you would then have to compare hole by hole with the original tape (8k bytes checked by hand!). (2) The other big problem is rewinding the tape. You have this streamer that is perhaps 50 feet long and pretty fragile. You have to roll it back up before you can use it again, or store it. We had a modified electric eraser to assist with this. But great care was needed to avoid tearing the tape.

Repairing a mispunched or torn tape was a process of gluing a strip of punched tape over the damaged area.

ErikFP 12:27, 15 Jun 2004 (UTC)


Oppose- Paper tape and punch card are completely different media: different shape, thickness, hole size character encoding, readers and writers, history, time frame, etc. The only thing they have in common is paper (and some paper tape was made of mylar). --agr 16:45, 18 January 2006 (UTC)

Oppose and comment- While they share some heritage back with weaving looms, cards went for a lot of information on single discrete units, tape went for information spread across one long unit. Ronabop 04:27, 20 January 2006 (UTC)

Oppose -- substantially different histories even though they resemble each other technologically. Atlant 12:37, 20 January 2006 (UTC)

Oppose- linking to Punch card in See also seems to be much more useful than merging disparate articles. Slark 07:22, 29 January 2006 (UTC)

Oppose- They're different media, with different histories and different usages. User:Ray Van De Walker

Character encoding[edit]


Which character encoding is used in this image? --Abdull 06:07, 8 June 2007 (UTC)

The image uses regular 7-bit ASCII encoding with the least significant bit on the right as usual, like the original text artwork it replaced. Note the line of smaller holes down the middle are sprocket holes, not '1' bits. Vanessadannenberg 14:52, 19 June 2007 (UTC) (author of said image)

I think that the "I" of the "WIKIPEDIA" example should be 1001001; however, the picture displays 1101001. We almost have the same trouble with the "K": its code ought to start with 100...(b7b6b5...), not 110. The letter W would be right. ¿Do you agree?

The text is in lower case except for the first letter "W". So the second and fourth letters are actually an "i", which is indeed 1101001. Same for "k". ★NealMcB★ (talk) 19:27, 26 July 2016 (UTC)


During a tour of the Titan II Missile Museum south of Tuscon, Arizona, we were told in an oral presentation that the target programming information was stored on paper tape for security. Although outmoded, it is human-readable, allowing easier detection of alterations.17:16, 6 October 2007 (UTC) LorenzoB 17:19, 6 October 2007 (UTC)

And where is TTS?[edit]

TTS was the standard six-bit code used in typesetters. It isn't mentioned here and doesn't even have a Wikipedia entry. (03:55, 4 July 2008

I added a mention and created a redirect teletypesetter to the teleprinter article which has a paragraph on it. Do you have more info on the code?--agr (talk) 11:47, 14 July 2008 (UTC)
There were a bunch of different codes. They were also used by wire services. The article isn't quite right when it talks about punch tape operated Linotypes; those punches were not Flexowriters but rather specialized machines that would keep track of how much space had been used on the line (using known character widths) so the operator could insert line end codes at the correct location. Apart from use for wire service material, punched tape operated Linotype machines were used for efficiency. The machine could run faster than most operators could type, so you could have several operators punching tape and then feed it into a single machine running flat out. Need to find a reference for all this. Paul Koning (talk) 20:56, 13 November 2015 (UTC)

Soroban Engineering[edit]

This firm, in Melbourne, Fla., made special-purpose wide-format paper tape punches and readers, iirc with as many as 40 channels. Of course, the tape was correspondingly wide. They also made a paper tape punch that could punch at 400 characters per second; the drive shaft ran continuously, and provided timing to the electronics that fed data to the punch.

Burroughs (not Philco?) made a floor-standing paper-tape reader with optical hole sensing that read at 1,000 chars/sec. and could stop the tape on the stop character. Of course, it had free loops between the drive and the storage reels. Tape was stopped by a very fast electromagnetic clamping plate.

Perhaps this info. could be included in the article; I didn't want to assume that it belongs there.

These are personal recollections, and would be difficult to substantiate.

Nikevich (talk) 08:44, 14 July 2008 (UTC)

1000 cps reading, with start/stop at any character position, was done earlier by Electrologica in Holland. 400 cps punch is amazing; it would be good to find a source for that. I do have an authority for another very fast punch, the Creed 3000 at 300 cps. Paul Koning (talk) 20:54, 13 November 2015 (UTC)

Common dimension of tapes and holes?[edit]

Could somebody please add some information on the most common physical dimensions used in paper tape operation, such as width (and maybe thickness) of tape, size and spacing of holes? Thank you! -- (talk) 04:56, 21 February 2012 (UTC)

Done.--agr (talk) 13:46, 21 February 2012 (UTC)

Monotype system[edit]

What width was the monotype tape and how many holes could it have across a row? Also, this article badly needs references to sources. --TedColes (talk) 10:11, 28 January 2013 (UTC)

The Monotype System article says 28 rows. A cross reference would make sense. Paul Koning (talk) 20:52, 13 November 2015 (UTC)

"Baudot" vs "Murray"[edit]

The article repeats the common mistake of referring to paper tape code as "Baudot" instead of "Murray" code. (See the article Murray code) As that article makes clear, the original Baudot code was optimized to minimize operator workload on a chording keyboard. Murray invented (?) the teletype paper tape mechanism and optimised his code to minimize mechanical wear, thus making changes from Baudot's code. Alas, the mistake is frequently propagated. I don't have a ready on-line citation, but when I was a teletype operator in the Royal Canadian Corps of Signals back in the early 1970s, we always referred to the 5-bit teletype code as "Murray code". In the interest of accuracy I think this should be changed in the article. -- AJWM (talk) 19:22, 29 January 2014 (UTC)

 Donerybec 20:39, 29 January 2014 (UTC)

Cryptanalytic devices[edit]

How about adding a section on how it was used extensively used during the second world war for cryptanalytic devices on both sides of the war, in the 30's and 40's. It doesn't seem to be covered in any way within WP. Here is an example: [[1]] This document describes a punched tape some 30cm wide, which was used in experimental devices, by the German Army, as an aid in the breaking of enemy signal intelligence. scope_creep talk 16:02 18 May 2014 (UTC)

Endianness for serial transmission / undulators[edit]

The image of a famous (but not necessarily standardized) serialization of punched tape, and my question at led to my recent edit here on left-vs-right. Clearing all that up would be very helpful and might be a nice illustration of the famously confusing world of endianness. ★NealMcB★ (talk) 21:56, 26 July 2016 (UTC)