5 Hole Paper Tape - Computerphile
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- Опубликовано: 12 сен 2024
- Before floppy disks and the internet, computers transferred data to and from paper tape. Professor Brailsford explains.
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This video was filmed and edited by Sean Riley.
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Back in the early 70s, I was a technician working on Teletype machines. I never saw any 7 bit tape, but with 8 bit tape, the 8th bit was used for parity, for basic error detection. There was also a 6 bit code, which was the 5 bit code with the 6th bit used for shift. This was used for ticker tape machines, where with the stock codes and prices there was a lot of shifting. The shift would also cause the printing to move over, so that the stock codes would appear on the top portion of the tape and the numbers on the bottom. This made it easy to scan through the tape, looking for a particular stock and then seeing the price. I worked in the Toronto Stock Exchange for a bit over 2 years in the early 70s and there were a lot of ticker tape machines in there.
can we have a video where Prof Brailsford talks about the evolution of computer technology? I'd very much like to hear what he thinks of the development. Did he expect computers to get to this point? Did it go faster or slower than he expected? What new ideas/technologies/concepts surprised him the most? Stuff like that. I mean, this guy is just a fantastic resource and really knows how to tell a story. Anyways, love the work you guys do. Love from DK.
+ Computerphile have these videos been done? Can't see a playlist
There is a third method of reading paper tapes. On the Myriad computers I worked on at the London Air Traffic Control Centre in the 1970's we had fast readers that measured capacitance through the tape with a hole offering an air dialectic and no hole a paper dialectic. The readers used capacitance bridges to detect the either hole or absence. They would read so fast the tape would come out horizontally for 3/4 feet.
The extension of terrible solutions into unheard of realms of performance and reliability by successive tweaking is something I find fascinating. These terrible solutions persist even when better solutions have been found, living on by sheer inertia and brute force of engineering, sometimes for decades until these obviously better solutions catch up and overtake them. Paper tapes is only one of many.
My favourite is hard drives. Here you have a spining disc, revolving ~100 times a second, with a tiny little magnetic needle on an arm whizzing about accurately hitting a tiny spot on the disc within milliseconds and reading up to about a billion tiny magnetic regions spinning past below it. This needle is suspended on an air pillow just above the surface of the disc. If for any reason it touches the disc, kiss your data good bye. This is jawdroppingly amazing and a ridiculously crappy and improbable seeming solution at the same time.
soylentgreenb What do you see as a "good" solution. SSDs? Goddamn magnetic tapes? Sure, your point is valid in a lot of cases, but you shouldn't go about criticizing existing, working technology unless you have a significantly superior replacement in mind.
Also, hard drives are still the most cost effective way to store a lot of data that still needs to be readily accessible.
+Lester Bailey Would love a video on this as well!
Another method would be through having small electrical brushes.
Simpler than measuring capacitance, but wears out the tape.
@@markevans2294 That's essentially the same kind of mechanical method mentioned in the video. I imagine that brushes, if done correctly, were a better mechanical option than rods since they should put less force on the holes but you probably had to replace the brushes or bend them back into place more often (based on my limited experience with brush motors and my sense of physics). I also assume they were braided brushes since non-braided brushes could potentially make contact with adjacent holes though I've never actually worked with this technology so I'm just guessing.
"Unshift on Space" was a common mode that you could set your TTY machine to.
So it would always go back to "letters" after it saw a space so you wouldn't be out of shift for long. Operators would send a "FIGS" again after a space.
My phone keyboard does the same thing and while it is sometimes useful it also drives me nuts sometimes.
And some people got in the habit of at the end of the line. Sending the line feed after the carriage return provided extra time for the carriage to move to the left side and the letters would ensure you were in letters mode at the beginning of the line.
I worked for a machine tool builder back in the early 80's and our first NC machines (the grandfather to the CNC) had this paper tape to run the program. I can remember having to "modify" the program with tape and a hand held hole punch. Cover up the holes you don't want, punch new holes, and hope it did not get caught on the pulleys as it was being fed through. Then came the floppy disk. It was about 8" in diameter and held 640k of information. High tech!
5 holes was not the shift. 5 holes was 'Erase' character, intended to be skipped on read. When you made a typo, you returned the puncher one position, punched five holes over that place, then you typed the correct letter.
But maybe there were multiple codes in use? I'm not sure. This is what I remember and it makes sense to me.
He mentions this, saying there are multiple codes not just one that is reserved for special characters.
You'd think the 5 hole codes would weaken the structural integrity of the paper at those points.
Johnnie Meredith
There's only 1 literal 5 hole code (excl. The center hole). The 0s are represented by the lack of a hole.
Ya but it would seem the paper would tend to rip sometimes in those instances.
Johnnie Meredith
Probably, but I also doubt that the purpose of this paper was to last very long anyway.
This is all quite amazing for me. I served in the US Army back from 70 to 77 in communications. I did some time with landline teletype as well as radio teletype, also did my time in the crypto vault where I set up the patches for radio and teletype encryption using the then modern day versions of the cipher machine.s
Pretty interesting about the state shift. This is exactly how a lot of mobile keyboards work now; You press a shift key to switch to numeric and punctuation keys.
4:00 "it's 10101, I hope that's the right way around to read it", lol, that one happens to be the same either way :P
And that's the letter Y. When I had a go at decoding that tape by eye, I got nothing but gibberish.
ryry
YZDBUBASEUEUEZ (assuming it is letters shift)
Think they just rattled some keys to make a tape to show. Being 5unit code, I assume it's unlikley to be binary.
@@gonzo_the_great1675 He did say he used that same kind of tape when he first learned to program so it could be program code.
The paper punch idea, probably came from all sorts of wooden cams of a machine, such as driven by a water wheel, music boxes with their windup, roller and "teeth" pins on it, and even the music players , rolls or flat metal disks. Data storage goes way back, but it was "mechanical", limited. I think some have said that a loom has some kind of mechanical data (of some type, perhaps the paterns) of some sort. Gears, wheels, can also store data of some sort, such as the mechanical counters.
Thanks for the memories! Remember that Teletype is a U/S registered brand name. The machine is a teleprinter, and yes; Creed made them in the U.K. The Creed 2300 was in popular use in Britain in the early to mid-1970's (the ones in Plymouth Poly had 8-bit tape punches and readers fitted), and it was a semi-electronic machine. Earlier models, such as the Creed 3, the 75 and the 444 were fully mechanical, and could be very noisy.
My Dad bought a punch tape computer for his company in the early seventies. It was a behemoth. He used to include a tour of the computer for visiting clients. I joined the company in 1983, and had to ask my Dad to stop the computer tour as the machine may not be as impressive as it had been twelve odd years previously.. :)
I could listen to this guy all day.
I also love him to know chemistry, math and computing almost from begining.
i worked for a company that built SCADA systems in the 1970's we would punch the boot strap into paper tape..once you were comfortable that the code was solid we would make a copy from paper tape to mylar tape to prevent the tape being torn ...we used teletype machines to punch the tape it was pretty slow going though and sometimes would jam.. and the PTR (paper tape reader) was LED's with photocells..it was pretty fast for the time period..all 8 bit tape..
The etaoin letter order (or a very similar order)as mentioned in this video is also familiar to those people who have an interest in cryptograms and cryptography. Somewhere around my house I have a program written in BASIC that was punched out on paper tape.
The following hole patterns (I don’t remember any actual patters except Null (leader/trailer) and Rubout) are immune to the current case setting of the printer:
Null or Leader: no holes, used to put labels on and to start reading; and Rubout: all five holes, used to “erase” a typo when caught immediately;
LTRS case: puts printer in letters case, and FIGS to put it in numbers case; note that if a single pattern were used to toggle, you could never get back in sync;
Carrier Return and Line Feed: you don’t want to continue typing at the right side of the paper and get nothing but a smudge; the reason they are separate (and CR is always first) is so that the first character of the next line doesn’t get printed on the fly before the carrier has returned to the left margin. Also, CR by itself can be used for intentional overprinting, and LF by itself can be used to avoid excessive spacing.
Can we see one in action?
Maybe the computer museum has one? There are a few videos of working teleprinters on YT.
Professor Brailsford is like a digital Attenborough. I could listen to him all day.
I've still got a box of paper tape in a plastic container in my basement. It was created by DEC (Digital Equipment Corp) and contains hardware diagnostics for the PDP-11/04
Is that for sale?
How similar is this to the tape used for old CNC machines? Up until at least a couple years ago, we'd go to a sheet metal guy who would whip up a CAD drawing, transfer it to a punched paper (or plastic?) tape, drag the tape to the machine, which would convert the data to something the machine could read, and ironically, punch holes in sheetmetal according to the original CAD drawing.
Mylar (which is a brand of plastic).
Between the World Wars amateur radio operators began to acquire used teletype machines to send Baudot code over the air as RTTY or radio teletype. It's still commonly used by hams today, even thought their computers now have over a dozen better digital modes.
in our hose as a child we had similar, but in mylar. one side silver, the other blue. wrapped around gifts as ribbon and punched upon it, Apollo guidance computer programming. no joke.
I'd love that thing
Great one. Very compelling, entertaining, and educational at the same time.
Really enjoy Professor Brailsford's videos.
Thinking about it, you could actually use a four hole tape for 8-bit ASCII. Just use registers to accept 4 bit data twice, and smash the two four bit numbers together to make an 8-bit code.
Register:00000000
Tape:1011 Four bit code,
Register:10110000
Tape:0101 Four bit code,
Register:01011011 Wallah! An 8-bit code! Send it off to the computer,
Register:00000000 Clear for next two paper codes.
I understand that this would be a slower process, but it would work great for an 8-bit machine, if it existed during that time.
+Quentin “SpecialBomb” Jankosky
It's a pity nobody came up with UTF-5.
0xxxx
110xx 10xxx
1110x 10xxx 10xxx
11110 10xxx 10xxx 10xxx
4 bits = 1 line
5 bits = 2 lines
7 bits = 3 lines
9 bits = 4 lines
You'd allocate the four-bit codepoints to ETAOINSHRDLU and a few other things, to maximize your overall coding efficiency. Then you have plenty of room for numerals and punctuation. Also, since the leading bits tell you whether you're looking at a multi-line sequence, there's no danger of starting at the middle of a tape and ending up in the wrong shift mode.
Unfortunately, long strings of digits would encode less efficiently than when using a shift, and it may be difficult for the telegraph service to explain why some letters are more expensive than others!
Samuel Morse invented a variable-length coding which was rather popular for sending telegraph messages. What's curious is that a variable length code was used even when sending encrypted messages where letters had uniform frequency.
That was done with 5 holes. With only 4 you wouldn't know where the character started.
Long RYRYRYR's made tuning easier- and it was nice to be able to hook a tape into a loop (for CQing) if the chaff didn't didn't punch all the way through.
Some five-bit papertapes were also designed with extra width on one side so that a readable character could be stamped next to each row of punched holes.
I bet when the tape broke it was at the 5 Holes.
Asymmetrical position for the sprocket holes - presumably to prevent putting it into the machine the wrong way around?
well, you are forced to put the sprocket holes asymmetrically, since it is a 5 bit code you can't put them exactly in the center
Also to show you how to read it the right way round.
Imagine writing a 4-bit ROM onto this 5-hole format, and using the "5th bit" to provide "tracking information" like on magnetic tape, that way through the computer could jump back and fourth to specific instructions on the punched tape ROM.
I'm aware of the purpose of the program counters role in a computer, but I think this tracking system could work well in conjunction with it.
I suppose you could just dump the whole progrm into RAM, but this way you wouldn't have to.
1:25 The sprocket holes were also punched as the data holes were being punched. So the tape did not have to be manufactured with the sprocket holes (synchronization track) pre-punched.
All holes punched in 5 or 8 hole tape, is a shift to "letters" case in 5-bit and was often used to rub out a mistaken keypress. And a null character in 8-bit code, no figures shift.
Einstein's photoelectric effect had to do with positing the existence of photons. It had nothing to do with inventing the photoelectric sensing tube. It was about how wavelength affects the emission of electrons. The photoelectric tube had already been invented.
I used to play with these when I was a kid.
At the place where my mother worked they had several machines.
I remember typing in some text, printing out the tape and then putting it in backwards to see what would happen.
Oh the memories!
i like how the sunblinds in the background become sharp through the holes :D
A channel with real intelligence. Keep up the good work!
a real humen bean
The use of paper tape to control an automated device doesn't go back to the 19th century but in fact to the early 18th century! Basile Bouchon invented a machine to help setting up a drawloom by using punched paper tape to set the pattern. In 1728, he changed the input from tape to punched cards similar to those used for the next 250 years, but it wasn't until Jacquard invented his fully automated loom machine in 1804 that the technology was widely adopted.
We used to test our teleprinters and reperforators by sending strings of ryryryryry. We also got very used to detecting that someone was inadvertently in figs because the fig shift character had been corrupted or missed out. Equipment made by Creed, Plessey and Siemens.
@trailkeeper yes actually. Looms from thetime of the industrial revolution would often store their patterns on punched hole cards, a similar method was used in mechanical musical instruments like player pianos.
Teletype was 8-bit no parity ASCII data. I love those machines. Telex machines were only 5 BIT.
My grandad used to work with paper based codes and technology back in the the late 60s into the 70s and naturally went into computers og geek love him
I see you 'rolling up' the tape thus causing 'pigtails'. Here's a clever method of 'winding up' the tape that I still use to this day on fiberglass tape measures. With the fingers of your left hand (reverse for left handed folk) wind the tape across the fingers in a figure of eight pattern. This makes a cupped shaped figure eight. To re-use, take from the center of the cup. The tape leads seamlessly without kinks. Depending on how large your hand is, quite long tapes can be tamed.
Long ago when I first joined the military, I worked in a career field where we used five level perf tape, for transmitting messages, and other things. The little hole is punched out of it. Tape is called Chad. And over the course of a shift or two, you could get quite a lot of Chad dropped into the Chad bucket. we had a joke that we played on new people. Towards the end of the role of a tape, there would become a reddish tinge to the tape to warn you It’s time to change. For new people, we would tell them that they needed to go through the bucket and separate the red Chad from the white Chad because although the white Chad can go out in the regular trash, the red Chad was for classified material and had to be burned separately. Was amazing how many people we caught on that……I was one of them.
How much information can one person hold?! Genius!
You could say figure shift and letter shift made a comeback with UTF-8. Also I noticed that giving the common letters fewer holes is similar to Huffman coding.
4:19 look at those compression artefacts on the tape with the window behind!
I noticed it because of earlier computerphile episodes! xD
+Little Lion That might actually be the pinhole effect, because compression jitters about in video. Here, it looks super stable.
One time, I was on the submarine and happened to have a cigar box, rubber band, and a paper clip. I took the chaff from the bit bucket on the SINS computer and put a whoooole lot in the cigar box. Taped down the rubber band to the sides, wound it up with the paper clip in the middle, and shut the top. Set the cigar box down on the mess decks. Oooo ... cigars!! ... asshole!! Even though I had to help clean it up, it was worth it.
Chuck why did you betray your brother
Hes no slipping jimmy anymore he's a real lawyer
Tried saving a SYM-1 program to a paper tape on an ASR33 teletype (mechanical reader, not optical) cause couldn't save to a cassette tape. Unfortunately, the teletype was two decades overdue for service, so that didn't work either. Grrrr.
I was fixing these tape punches and readers in the 90's.
0:44 No, 32 possible codes. The number of different characters that the Baudot code could actually transmit was 52.
It must have been amazing to be able to completely understand all the machinery that you were coding on.
I started my career in telecom as a bench technician, overhauling Teletype machines. Later on I was a computer tech, repairing computers, even getting down into the microcode on some models. Then I bought my first computer, an IMSAI 8080, which came as a kit of parts and bare circuit boards and wrote my own software for it. Back in those days, people knew their computers inside out.
Wow, I remember using this in the 70s.
The more i think about it the more weird it gets with reserved combinations, it seem given 5 -bits you could actually encode anything using lookup tables. You could chain the encoding semantics not just toggle between two states. Using something like a binary min max search you could encode things shorter than their actual bit representation.
For example we could encode a 32 bit pixel or combination of pixels using this principle and it will find the actual bit in less using less bitsteps than the actual bitcombination.
But the encoding will be state sensitive, so what you get is a result from the original state, what is this? Is there math that describe such properties of encoded lookup tables?
It seem almost magic.
Same thing with video and keyframes as in needing to resync for an out-of-whack letter-shift or number-symbol-shift. The picture gets messed up on corrupted files or streams until there is a keyframe for resync.
Five hole paper tape was guaranteed to be encoded under the Baudot encoding if textual data was punched on the tape.
One question that came up for me during the discussion of copying was that of media costs--how much blank tape (in feet, meters, or characters) did you get for a pound? Or did you buy lengths of plain paper with the right width and run them through some sort of friction-fed machine to punch the sprocket holes, and then through the actual output punch to store the data? The latter seems less likely but I wouldn't be surprised either way.
Thanks!
I don't recall the cost, but you'd buy the tape in big rolls. 8 bit tape was also available in "fan fold", which was preferred in computer rooms. There was also mylar tape available for making permanent copies that wouldn't wear out.
that is pretty awesome why have I never heard of this before
Etaoin shrdlu was key to the Linotype machine.
But why 5? Was 6 too much for the machines of that time to handle? You would not need a number/figure shift if you had 6 bits.
If you add a sixth bit to five you are effectively increasing the data rate by 20%. Actually there is a start and stop bit but regardless you would be charged for the extra data. "Telegraphic" used to be a synonym for "terse".
There was a 6 bit code used for ticker tape. With stock prices, there was a lot of shifting, making a 6 bit code more efficient.
4:22 Interesting artifact of the video deinterlacing? Suddenly the tape seems like it is shredded into transverse ribbons.
I worked on the telegraph service and they always called it 5 unit code.
why does Einstein get credit for the photo electric effect. wasn't the effect described by Lenard first?
We used that code and readers well into the nineties in the USAF... Anyone remember the ASR 28 Teletype? This was the Cadillac of the teletypes to me.
Yep, I used to overhaul them half a century ago. I also had an ASR 35 connected to my first computer, an IMSAI 8080.
pretty cool
IIRC optical reading was used with the Colossus cryptoanalysis computers in the 1940s.
They had to, as mechanical means couldn't keep up.
@MrGareth66.com if you look up videos on the Altair 8800 on RUclips there is a channel that shows off a teletype with paper tape interface. It's very loud.
Would the sprocket holes be analogous to a computers clock signal?
Trevor Viken The sprockets are *driven* by -- or at least adjusted to -- the computer's clock signal.
For Colossus, the first electronic computer used by the codebreakers at Bletchley Park, the paper tape actually functioned as the machines clock. But this was unike for that application and I suppose the tape, which ran in an endless loop, was friction driven, because the idea was to read the tape at maximum speed. Colossus predecessor, the Heath Robinsson, used two tapes in two separate loops, one tape one character longer than the other, and consequently those tapes had to be syncronised and could never run as fast as the single tape on the Colossus. On Colossus the characters representing the second tape was set up on a plugboard.
No. it was for pulling the tape through the reader, though optical readers used it to clock the character in.
Is anyone else reminded of Douglas Engelbart's chorded keyboard with the original input device for this thing? I wonder if he saw it.
The center holes are like a clock signal. Every so many clock holes, you have the next character.
But the hole or no hole were not referred to as ones and zeros but as marks and spaces harkening back to the days when morse code was recorded on paper tape as dots and dashes.
Etaoin Shrdlu was both a freedom fighter against the Ottomans and a leading figure in the C19 Albanian literary revival.
@Stephen Kamenar I've actually seen a guy use a paper tape to load BASIC into an Altair 8800.
Yeah, that's guy's name was Bill Gates! He "borrowed" the computers at Harvard to develop the BASIC for the Altair. Those computers were not supposed to be used for commercial purposes.
That sequence of the most-used letters in the English language: "etaoin shrdlu" - it looks kind of like Irish/Gaelic! (Or maybe Welsh?)
How do you know if you're a really old computer programmer? Your first programs are stored on punched paper tape! I'm a really old computer programmer! (Not really, *really* old... my tapes are 7-hole, not 5-hole.)
We had a small app that converted a text string into dot matrix letters punched into the tape so you could "label" a tape with the program name. Ah, the memories! :)
Why the last bit always 1? Some kind of a check? In this case it's only 4 bit
IBM 1403 printers used a mylar tape to control feeding of the paper forms.
I was there Gandolf, 5000 years ago...
So he had the forethought to assign the most common letter (E) to a single punch to reduce wear and tear, but not enough to only use that punch in conjunction with others for the rarest letters? That one side of the tape has a hole punched nearly every single line - that punch will wear out several times faster than all the rest anyway.
A good point, but if you study the Baudot-Murray code you'll see that E has just a 1-bit at the left and T has just a 1 bit at the right . And the very rare letter Z (in English anyway) has a code 10001 (which combines the E and T positions). I've sent off a link to my PDF sheet on the Baudot-Murray code, to Sean, and am hoping he can add this to the info page for this video soon. It's instructive also on that sheet to look at the B-M codes allocated to "A", "O" etc.
I've actually memorized this entire five-bit code.
Inexplicably, the letter Z is only two punches.
That's a useless ability i want to develop :v
I was using paper tape in 1988 to make sheet metal designs.
if they had truble with 5 holes having limited number of combinations why didnt they use 6 or more ?
The question is: How many forests would Micro$oft have to pulp to distribute Windows 10... Any, how many weeks would each user have to wait for the vast reels of paper tape to be read. One would just get it loaded when another security update would be delivered by truck...
Can you have someone on telling us why TTY's are called TTY?
In *nix systems we have TTY1, TTY 2.... TTYn, would be interesting to know the story of the TTY emulator/system that is so prevalent in *nix systems.
Also what a PTY is.
The first Unix machines were accessed by teletype machines (that's where TTY comes from). PTY is, I think, "pseudo-TTY".
TTY came from TeleTYpe. PTY likely meant printer
Back in the dark ages, those computers used TeleTYpe machines for a console as well as tape punch/reader.
it bothers me that it is not 6bit to make it symmetric around the sprocket holes...
would also give you 64 symbols...
was it done to make sure you read it in the right direction?
Yes, the "right direction" was a big bonus with an asymmetric line of sprocket holes arising from an odd number of bits As you put the tape into the reader you couldn't engage with the sprocket holes if it was the wrong way around! Also the rule was (as I recall) that if you lay the tape horizontally with the narrow band at the top then reading down the columns top-to-bottom would give you a readout of the Baudot-Murray code
RoySchl But 20% more bits to transmit, 20% more mechanical parts, etc., all for very little gain. (Until there *was* lots to gain. And then they jumped to 7 bits (which allowed for a parity bit or extended characters).
You mention Baudot, and I can't help but notice the similarity to the character rate of my old modems which were classified by Baud rate. Any connection?
Indeed, "baud rate" is named after Baudot
Inferior English has only 26 letters.
Here take some tschsh's щщщщ.
Crazmuss How is that inferior? Would you call binary overly simplistic?
That's cyrillic latin is this ššš
Sašo Domadenik It's not really 'š', but close enough ;)
Crazmuss y u do dis щ(
Paul Warelis How is that everybody use hexadecimals if binary is so great?
Fun fact: A tape storing only 6Gb of information would be long enough to wrap around the Earth.
Was there not a version that instead of a physical punch it used high voltage electricity to explode a hole through the paper?
frollard yes, the faxes did that
in terms of longevity of the media, am putting my money on paper tape and punch cards to outlast magnetic media as dating from the same timeframes
For the character limitation I wouldn't have ever thought of inventing a shift key, I would have just used the existing alphabet to do Roman numerals or something like that
I accidentally reversed engineered the shift key in the shower while thinking about how to let a Turing machine know whether a piece of data was holding input or code... the great problem I wanted to solve was how to make a computer out of macaroni pieces because I heard that line in a song.
Even with that I didn't made the connection between that and shift keys :v
lol "Sensible European languages" - yes we are looking at you Finland! ;)
Also the cause of occasional snow fights in summer!
They really screwed up picking a bare minimum 5 bit instead of 6 bit. 64 combinations would of given a much more useful character set with control characters to boot... also you could avoid or set as the least frequently used characters some of the more hole ridden characters like 11111 or 10111 or 111111 that would make the tape really weak at that point.
There is a later 6 bit code called TeleTypeSetter (TTS) used by newspapers.
The early applications needed just upper case letters, numbers, and a few punctuation and control codes. It was many decades before computers were invented
etaoin shrdlu is a Linotype-ism
reminds me of the WITCH computer, you guys should do that
cool
mesmerize
That stuff I'd cool, got some off Colossus.
What language were the programs written in?
The 5-hole tape I was using for the video came from the EDSAC rebuild project at Bletchley Park. (EDSAC was a pioneering first-generation computer originally built at the University of Cambridge; it went into operation in 1949). Sean is hoping to do a video on this project fairly soon. The particular tape I was showing contains a classic test program for EDSAC, which calculates the first few primes. In those days, and well into the 1950s, programming was done in assembly code specific to each machine's architecture. General purpose higher-level languages such as FORTRAN and COBOL began to appear in the mid 1950s
Great, assembly in that case then. I hope to see the edsac video
Cant fit all symbols on a 5 bit hole punch? Make it 6 bit. Now you have 64 spaces. Still not enough? Do 8 bit then. 256 spaces... isnt that enough?
@@The4stro There is also the problem of making the tape too flimsy. Punching 4 out of 5 holes on five or more consecutive characters makes for tape that can tear or break easily in a mechanical reader. Check the previous video on punch cards. I was not aware that no more than 2 holes per column were punched, probably for a similar reason.
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