Back to the Fax Machine 

"A genuine mobile fax machine! No don't start now, it's not plugged in yet."

Only Matt Parker would edit the video so that the viewers would know the trick wasn't edited.

"Download a fax app" is definitely not a phrase I ever anticipated hearing

Matt Parker almost tricked me into believing that nobody owns fax machines... Then in 2019 I moved to Germany and oh boy, what a surprise.

One of the first things I did after adding a Hayes 300 baud modem to my Apple ][+ back in 1981 (after dialing in to some local BBSs) was to compute fax images, and use the fax as a printer that would be much quieter than my noisy dot-matrix printer. But the lack of memory to hold an entire page at 200x100 DPI (approximately "Standard" fax resolution, ~200 kB/page) meant I couldn't simply plot lines and draw characters into a large bitmap. I had to get a bit more clever. My first thought was to have a representation of the plot and/or text I could then rasterize to a file on a floppy disk, but this rapidly became way too complex to implement quickly. I then noticed that the vast majority of fax dots were left white (not printed). When meant that an RLE (Run-Length Encoding) would be extremely effective. In RLE, you have a dot value followed by how many times it is used sequentially. I wrote a program (initially in UCSD Pascal) that would plot dots within a binary RLE representation of a fax page. Let's say an empty fax page is represented by "0[200,000]", which is simply 200,000 white (unset) dots. Now, let's say I want to plot a horizontal line that's 2 dots thick across the middle of the page. The resulting RLE expression would be: "0[99,300],1[400],0[99,300]". Even as text (binary is far more compact), that's a small representation of an entire fax page! The other advantage of RLE is it is ridiculously fast and easy to decode on the fly, far faster than reading uncompressed raw data from floppy, and fast enough to keep up with the fax mode of the modem. I added functions for drawing simple fonts, lines and conic sections (using Bresenham's algorithms) and went for it. Creating the representation was easy, but I had lots of trouble sending it as a fax. Documentation back then was fairly sparse, and I had to reverse-engineer the details of the Hayes fax commands. I soon learned that UCSD Pascal was poorly suited to real-time programming, and rewrote the fax send program in 6502 assembler. When I did this, I also wrote a program that would take my RLE fax files and send them to my dot-matrix printer (which was much cheaper to test with since fax thermal paper was expensive at the time). Of course, I soon learned I wasn't the first to attempt this, nor was I the best. By the time I finished my code, even Hayes had released a program and library that covered 80% of what I had done. All I did was port my code to draw conic sections and arcs. Later I added various spline functions. Then flood-fill of closed objects. Then I added dithering for filled areas. Then I switched to an MS-DOS PC and never touched the code again.

I have never laughed harder at a live performance regarding the life, death, and revival of the fax machine

If I pay enough, can you fax me the VHS?

9:23 you can't fool me, that VHS still has it's tab on. Aren't you worried about someone taping over it with some under par maths comedy show?

Is that a machine capable of both phoning and faxing? Please, please tell me you called it the faxophone

The NHS is believed to be the biggest purchaser of fax machines in the world - I don't know how true this is because I can't bothered to fact check it. But what is true is that the NHS runs on fax machines, especially when it comes to communication between GPs and other parts of the NHS. I'm not terribly upset by this because it has a fair few advantages. 1) Because not many people have faxes it's really difficult to send confidential information to a random person by dialling the wrong number. 2) Actual signatures are transmitted, so if I want a GP to prescribe something for my patient, the fax, that I can put in the patient's notes means that it is a legal prescription. 3) You can't CC everyone in the NHS and bring the whole thing to a halt. 4) You get a nice receipt which means you are certain that your message has be received (whether it gets acted on is another thing...) So for something from the 1800's it's not a bad bit of kit. And a lot easier to use than the official NHS email system where it's all web-based.

Only two things are certain in life - death and faxes

Post-fax world!! And alternative fax!!! Matt Parker, you are a genius. :)

hah, I rewound and watched it again to find where the ties went on just before the pause bit appeared.

I wonder how many times per day he gets a fax of a Parker Square?😄

Parker fax machine

I love every second. It's easy to understand, well thought-out, and looks amazing. It's clearly one of the best Venn diagrams ever made. Oh, and the show was ok too.

I wish fax machines were as dead as he seems to think. I had to stay late at work last week because someone faxed us a 150 page document that took 90 min to print full of extremely confidential client information that I couldn't just leave on the machine for some random janitor to see. Except that the fax didn't completely go through. So they tried again. And again three more times the next morning. That was a fun day.

I was in the audience for this, I tried sending a fax to it but it ran out of paper

I live in Canada and work in a Hospital where faxes are still used. It's still the best way to get a patient's chart summary from an other hospital.

You're one of my favorite comedians Matt, I'm downloading now! Can't wait to watch in full!

Michael J. Fax

I wonder how many parker squares he has received over the fax.

Hi Matt! I have just come from your wonderful presentation at the Open in Norwich, where I secured your autograph. Everyone absolutely loved it- it was the best presentation so far in the event's history. Thanks again, JP.

2020 05 03 - No way - as of today this number is still valid... Added to my contacts so that I can "drunk fax" Matt Parker all the way from South Africa!

There was, in the 80s, a product called "The Complete Communicator" which allowed a DOS computer to recieve a voice message and call you with the "Voice Mail" for 999 Voice Mail boxes. It could also send fax as a selection from a menu or receive a fax with a voice comment. You could even send a file, any kind, to another computer using "The Complete Computer" as a fax. This would be useful today as, if intercepted, the file is seen only as a black page. If this wasn't enough, you could pipe a call to another program, BBS Host, for the duration of the call; something I used. Then came Windows.

I can't believe they predicted the rise of Alternative Fax!

Bought a copy, downloading now.

Awesome! I didn't know these were available! Can't wait to see you on your inevitable world tour :)

I was impressed by the double tie and I re-winded the first time I saw it come out. Very well played.

There's a surprising number of weird things that use faxes (at least in the U.S.), especially if you need to send someone a signed document. As a result, a scanner hooked up to an internet fax server is one of the more popular services offered by the public library where I work.

Can we get a laserdisc version?

Wow! Doing it in VHS and selling for £3.14. Love it!!!

That fax machine better still be in operation.

That's not very mobile. What you need to do is build it into a back pack and call it the FaxPax.

The only thing holding me back from going and getting some kind of program to send faxes to that machine is that this video was posted five years ago and I'm not sure if Matt is still paying for cell service for his mobile fax. Sending a fax that can't be received would just be pointless, right?

In case the fax machine is still active someone will probably go overboard and start mailing you daily parker squares or something. (maybe me)

Banks, realtors, and government offices still use fax machines a lot in the US.

Haha! I was just checking if I missed you put the ties on and I thought to myself "must be a camera cut" or "that's why it cuts away"! Cheers for the explanation!

Parker stand up

Just bought the dvd super excited to get this in the mail.

Very entertaining... love all the fax and figures

Yes finally available to my country! The previous Amazon versions weren't available - soooo psyched! :)

Full of interesting Fax!

Man, a bttf AND a Jurassic Park reference. This man is living the peak of cinema.

A post facts world. Alternative facts. Yep, VERY prescient.

Aha the Jurassic quote "didn't stop to think if i should"

Wow. Drunk faxing sounds like something I would do. Is your fax (omg there is a fax emoji 📠) still live? Or... Working... Or whatever the appropriate term for a fax that can receive faxes is?

Man, you're a inspiration. I study Applyed Mathmatics in FGV, Rio de Janeiro, and here he have this talent show, the Fibonight (I know, the name is great). I thought "I can make people laugh like Matt Parker" And I told a lot of jokes there, in froint of my professors. The reactions was variable, but my professors liked, and some other students too! I told one or two jokes of yours in Portuguese, but most of all was selfmade.

Fax machines are still used in the US, mostly for secure document transfer. The biggest users are the medical establishment and utilities like gas, water and electric. While they do transfer internal documents by intranet, and communicate with customers by email, many still require that signed forms be sent by fax instead of a PDF over email.

Zero Fax Given.

Exchange rates may vary but mathematical constants won't 😂😂

Regarding the mobile fax machine, we were using the Lightweight Digital Facsimile model # AN/UXC-7 mounted in vehicles during Desert Storm 32+ years ago.

Matt, When ever I see your stuff I think of a train from London to Paris.... EuroStar... (Your a star)!!!

The fact that you have it on VHS is amazing

for the first few minutes i kept on thinking: what parker resolution, this isnt 1080p.

"Prime Faxtors" he did not just do that

In US buy and use fax machines all the time as part of all-in-one printers (print, copy, scan, fax). Still use fax to place orders with broker - sign the form and fax it over. Fax lives! : )

at 1:34 my brain exploded from too much meta

9:33 hope you remove the square bit at the front so you can't accidentally record over it. The front looks really clean and simple, Did you edit any of it in afterefax?

Mobile Phones had fax capability before apps, that is you could connect a mobile to a fax machine. The service option codes are 0x5 for a Group 3 Facsimile at 9.6kbps and 0xd for a Group 3 Facsimile at 14.4kbps. You would get a separate directory number for your mobile fax and then when it was called you were paged and served with that service option code. This was important because the voice coders used would filter out some of the frequencies needed and therefore needed to know it was a fax.

Brave to put this online! *sends Matt a fax*

Added to my Watch Later list, so I can drunkenly fax Matt various images of wildlife and exotic desserts later this week. I'll keep you dudes posted.

than you for your work, best wishes

That double tie add on you did was smooth

In 1966 fax technology used revolving drums that had to sync up on both ends. The sending unit would scan slowly across as the drum revolved under the scan head and the receiving unit would typically use a thermal paper to print on the drum. And, you could sit there and watch the spinning image appear (left to right if I recall correctly) as the bottom of the paper went flap, flap, flap...

receipt paper on an accessory for an iphone with a fax app, and you've truly made a portable fax machine.

Ah Matt Parker in all his StandupMathy goodness, only here on Numberphile would you find su- _nevermind_

I see the A-fax and B-fax, but sadly Ceefax is no longer with us

There are surprising amount of places that still use Fax Machines XD

every office I know still has a fax machine...

Quick! Someone fax him a picture of Rick Astley!

I don't know about fax machines, but just a few days ago, I found that my cell phone could connect wirelessly to an unsecured printer in a random office in an office building. That could be what was actually depicted in BttF2, and we wouldn't have known the difference at the time.

I can confirm the tie thing, I was there :-) (#humbleBrag)

Alternative facts is still hilarious in 2021!

Is it plugged in now?

We live in a post fax world? Let me introduce you to Japan...

I work for the NHS in a GP surgery and fax use is integral to everything we do. I don't know what we would do without it haha!

I just love the self-fullfilling-prophecy-joke of that the 2 tide trend x'D

7:54 could you call it the "faxual revolution?"

"I spent so much time thinking about whenever I COULD that I forgot to think about whenever I SHOULD" xD That line alone is already worth more likes than YT allows (hint: more than 1)

I loved the special double tie E-fax

it's not my favourite math constant, it's my favourite math constant divided by 2

I use fax machines quite a bit. Probably enough to have one in my home. What I don't have is a phone line.

Ow, that VHS release 'joke' just made me choke on my tea!

The Swedish police still uses the fax machine when they send internal memos to their bosses.

As Martin goodman said, "so you don't have to read everything of a bloody screen!"

Leave it to a mathematician to explain his only magic trick immediately

I got this suggested after I had watched a video about the fact that the German Federal Constitutional Court only accepts letters and faxes but no e-mails.

It was very common in Spain for some companies to ask you to send a fax to i.e. end a phone line contract, assurance etc Seems that It's mostly dead by now but I won't be surprised to know that public administration and some companies use It to send invoices, POD's and things like that.

I rewound to see you put the ties on and I saw it then you came in to tell us about it and I was sitting there like "I already know".

This is why I subscribed you years ago

Did I hear Tau YES PLEASE!

In 24/7 industries that can't switch off without catastrophe, there are lots of instances of outdated technology being used; I work in energy, we send and receive a whole lot of faxes. Someone recently joined the company I work for who was previously in shipping, where they also faxed a lot.

I have never seen a fax machine in my life

actually, as a lawyer, we still need to use a fax all the time.

How faxinating

an 0141 number? So, Glasgow is where the fax revival started?! PS. Thanks for the handy Christmas gift (already ordered DVD+DL limited edition)

I had no idea any of these were available online, I was always rather sad that these were only in the UK and I'd likely never see one. Now I have this one and Full Frontal.

Oh my god, after the video ended I got an ad for a fax machine app

Drunk faxing is the best!