Binary to BCD (Double Dabble Algorithm) - Computerphile

Double it and Dabble where required - The neat trick that turns pure binary into binary coded decimal. Professor Brailsford performs the magic!

This video was filmed and edited by Sean Riley.

[FourthDerivative]

And when the nibbles double dabble with a paddle in a bottle and the bottle's on a poodle and the poodle's eating noodles, they call it a poodle noodle bottle nibble double dabble muddle.

[SuperUtube]

Been a programmer for more than 40 years and fully understand both binary and decimal and binary coded decimal and yet this video makes something simple look complicated!

[chipacabra]

One of these days, I would love to hear Professor Brailsford talk about Big Endian and Little Endian representations of numbers.

[CarzyNavi]

I love the fact that they always use the retro printer paper in every video... what a good use of outdated stuff... XD

[sebastianelytron]

I'm a simple man, I see a Prof Brailsford video, I break the laws of nature and the speed of light with how fast I click.

[ShipOfFreaks]

should clarify that you only add 3 *if there are still shifts left to do*. if on the last shift you get values of 5 or greater that's fine.

[NeilRoy]

Always a pleasure to listen to him. Never a dull moment, at least for me.

[timoteedrimes]

he is doing the dabble
**two times in a row**

[hidroman]

"You can go and dive in there till your heart's content" it'll be, Sir, it'll be ❤️

[MattLohkamp]

so this method works up to 4 binary digits (15 in decimal) - can you extend it to work in 5 digits (31?) Does that just require an additional bit in the tens and units groups? is 11 (3) still the magic number to add?

[grantnichol]

Whoa, I actually commented on the BCD video saying that the double dabble algorithm was useful for converting binary to BCD!

[SECX]

You know, having to make something work with a microcontroller and assembly make more sense to learn about this stuff than just listening to this guy and doing some exercise on paper.

[aidywady]

You explain this very well. Thank you for the video🙂

[MrCyanGaming]

just remember, greater than 4, add 3

[gordonrichardson]

Someone asked about Double Dabble in the previous video. I didn't expect that algorithm to be included in a video.

[blahdelablah]

Seems like there could be a far better way of handling this, either through hardware or software. Just use an AND gate or operation on the first and third bits of the nibble, and if the output of the AND gate/operation is 1 then that goes to both the carry pin of the next nibble and the reset pin of the current nibble.

[DzDesignHD]

This was awesome, thank you for showing me this :D

[johnlister]

Or:

L R1, <binary number>
CVD R1, <bcd number>

Included in real machine architectures since the 1960s...

[Hampstead]

By tweaking the algorithm a little, we can do any base.

[kamosevoyan]

Could anyone tell me floating number representation algorithm? Please.