5 ms·
The Land Before Binary
- xellisx 8y agoComputers used to run on food...
- Swenrekcah 8y agoAnd run for it on foot
- burlesona 8y agoThis was a fun read, thanks for sharing!
- roywiggins 8y agoThe Harwell WITCH used Dekatrons, which is a device that has 10 states and can therefore store one decimal digit each. https://www.youtube.com/watch?v=vVgc8ksstyg https://www.youtube.com/watch?v=vVgc8ksstyg
- bbeonx 8y agoWhat's up with the binary representation of 11?
- __david__ 8y agoThe 2 of 5 encoding reminded me of "8 to 10" codes [1], which (as far as know) is still in use by disk and tape drives. It's for a slightly different reason than the 2 of 5 code but it's roughly the same idea. [1] https://en.wikipedia.org/wiki/8b/10b_encoding https://en.wikipedia.org/wiki/8b/10b_encoding
- userbinator 8y ago...and those have been expanded to even bigger units: https://en.wikipedia.org/wiki/64b/66b_encoding https://en.wikipedia.org/wiki/64b/66b_encoding Disk drives use a variant of RLL: https://en.wikipedia.org/wiki/Run-length_limited https://en.wikipedia.org/wiki/Run-length_limited
- Sniffnoy 8y agoVarious corrections: The article says that ternary uses exponentially fewer symbols (actually, in further nitpicking, it says "bits" rather than "symbols") than binary, but that's not correct. The decrease is just linear, by a factor of log_2(3). The comment about subtraction being a lot easier doesn't really make a lot of sense in light of 2's-complement notation; yes, it's a tiny bit easier, but... (the comments about sign bits also seem a bit out of place in this light).
- adamnemecek 8y agoAnalog computers are even more interesting and I predict them to make a comeback.
- bogomipz 8y agoCan you elaborate on why and where you believe they will make a comeback?
- deleted 8y ago[deleted]
- adamnemecek 8y agoThey can solve optimization problems better than digital computers. It's a wholly different paradigm, for example the analog sorting algorithm has a runtime of O(n). It's called spaghetti sort. https://en.wikipedia.org/wiki/Spaghetti_sort https://en.wikipedia.org/wiki/Spaghetti_sort There used to be electric analog computers. I've been working on an analog photonic computer (very theoretically so far) that I think could work. Do you know how many electrons you move when you execute an instruction? It's like on the order of 10^18. I might be able to get away with a couple of photons.
- Vekz 8y agoPlease keep us all updated on your work. Would love to see some blog posts or something.
- adamnemecek 8y agoLol you can bet that if I manage to pull this off you'll hear about it. The problem with blogging about this is that it diverges from current status quite a bit and as a result I've been called a crackpot. But I'll show them all lol.
- alfredallan1 8y ago
- saagarjha 8y ago> POSTNET (the old barcode system the Post Office used to route mail up until a few years ago) Oh, are these not in use anymore? > The first group had two bits, one representing the number 0 and the other representing the number 5. The second group had five bits representing the numbers 0–4. Sounds like an abacus to me…
- Animats 8y agoTelephony used 2 out of 5 code extensively when passing dial digits around within the system.
- DrScump 8y agoI wonder if bi-quinary decimal influenced the later Packed Decimal (known as COMP-3 in COBOL), which stored numbers in just over half the space of the text equivalent (e.g. a 7-digit number would need 4 bytes).
- aib 8y ago> (FYI I’m going to reverse the conventional order so that the 2⁰ is the left most throughout this post) Um, why would you break (or rather worse, invert) such a common convention? > So 11 is 9+3–1. ...and not follow through, just two sentences later? > [...] at which point the number 11 would be 2-0-1 (1+1+9). Surely you mean 2+0+9 or 9+0+2?
- YeGoblynQueenne 8y agoAnd let's not forget Charles Babbage's Difference and Analytical Engines, both of which were decimal-based. And mechanical :)