Fifty Years of Transistor-Transistor Logic

http://www.embedded.com/electronics-blogs/break-points/4431173/TTL-turns-50--more-or-less--in-2014-

by gumby • 12 years ago

98 34 12 years ago

pessimizer• 12 years ago

This link cuts off the article before the last couple of paragraphs. This is a better link: http://www.embedded.com/electronics-blogs/break-points/44311...

dang2• 12 years ago

Thanks. Changed from http://www.eetimes.com/author.asp?doc_id=1322881.

Edit: We also changed "TTL" to "Transistor-Transistor Logic" since too many comments were about that.

recentdarkness2• 12 years ago

Funny I thought of "Time To Live"

circa• 12 years ago

same here! haha!

recentdarkness2• 12 years ago

Very funny to be downvoted on a renamed title....

tcas2• 12 years ago

I still have a copy of a TI TTL Data Book, completely useless these days with the internet, LVCMOS everywhere, all in one microcontrollers and FPGAs, but it's still cool to flip through every so often.

pling9• 12 years ago

I have the same book and it gets used regularly. Surprisingly not everything involves gate arrays and microprocessors.

tcas2• 12 years ago

I know, completely useless is an exaggeration. I just find it much more convenient to pull up a searchable/zoomable PDF vs flipping through the book when I do need to check a specs of a 74/54 series chip.

cicero• 12 years ago

One of the best courses I took at Texas A&M in the late 80s was a digital logic course. We started with boolean algebra and Karnaugh maps. Next we would draw a schematic for a circuit to implement the logic. After that, we would get out our TTL Data Book, a required textbook for the course, and find the parts we needed to build the circuit. There was a room where you could hand the attendant your parts list, and checkout a breadboard and chips so you could build your circuit. Finally, we would connect the circuit to a scope in the lab and make sure it worked. I loved how the course took us from theory to practical hands-on experience.

mpyne• 12 years ago

I have the same memories of a UNF required computer lab course in 2002 or so. We were required to learn about flip-flops, various other hardware gates, and using truth tables and clocks to form hardware logic.

By the end of the course we had to make a 4-bit breadboard CPU that could handle a couple of operations; a push button acted as the "clock". It was all very simplistic but at the same time I learned an incredible amount about how computer hardware works.

arno_v• 12 years ago

That is quite a long TTL!

smutticus• 12 years ago

I also read this and thought, Time To Live.

ChuckMcM4• 12 years ago

I've got a couple of PDP-8 computers and they are all TTL. Its fun to pull out the three boards that make up the CPU and point out individual things like registers and instruction decoders, but its also something we'll probably never do again.

As an intellectual exercise, when Intel announced their 28nm parts a friend and I tried to estimate if you could get the entire TTL catalog into a single part. Turns out you should be able to, pretty trivially. We imagined a fun (but useless) part with 14, 16, or 24 pins that you could drop into a programmer, pick which chip you wanted and "poof" it would be there (every chip would have every component in it). At that point an FPGA makes more sense though.

Some of the 'classic' parts, like NAND gates and inverters are still pretty useful in teach digital logic concepts, and its fun that folks using Arduinos and other pin limited devices are using shift registers to get more effective pins, but the heyday of discrete logic is well and truly past.

pling9• 12 years ago

Ive done a fair bit of electronic design over the years (professionally). The classic parts are still going strong. There are even single gate devices now in SMD packages!

Outside the world of computing and mainstream consumer tech I expect to see our friendly TTL devices and op amps etc and even discrete transistors live another 500 years or so. Some problems are quite cheap and simple to solve with them and they're well understood.

(I'm building a laser harp completely out of discretes, logic and analogue components at the moment - not a single microcontroller or CPU in sight. Even hardware MIDI :)

jacquesm• 12 years ago

Please, please, pretty please, document your building of the laser harp and do a write up. That's a thing that I've always wanted to do since I saw JMJ, it's an absolutely incredible concept and a nice DIY write-up would really make my day.

ChuckMcM4• 12 years ago

That is pretty awesome! By 'hardware MIDI' I'm guessing you're triggering a shift register which dumps its contents? Do you do after touch effects?

paletoy3• 12 years ago

The classic parts are still going strong.

But there are very good alternatives for them, be it low cost mcu's,50 cents fpga's, or even lower-end programmable chips from sillego[1][2]( going down to $0.2/10K + probably $0.1 more for programming - and that's without competition). Those are smaller, more reliable(less soldering) and can do quite complex functions including analog.

So i wouldn't bet on simple gates holding on for 500 years.

[1]http://www.eetimes.com/document.asp?doc_id=1279013

[2]http://www.silego.com/buy/index.php?main_page=product_info&p...

simcop2387• 12 years ago

CPLD's are the step between discrete logic and FPGAs now. You can look at them as exactly what you describe there. They're a great way to implement things when an FPGA is too power hungry or too expensive.

http://en.wikipedia.org/wiki/Complex_programmable_logic_devi...

stox• 12 years ago

You must have later PDP-8's, the early ones were DTL, Diode Transistor Logic.

ChuckMcM4• 12 years ago

Yes, technically I've got three (8/E, 8/F, 8/M) which are all TTL, the PDP-5 is DTL however :-)

InclinedPlane• 12 years ago

TTL is one of those remarkable achievements that is so blindingly obvious and elegant that you wonder how everyone got along without it. It makes you wonder what sort of similar advances will happen in the next few decades which will make some aspect of the way we do things today look hilariously complicated and outdated.

ecesena2• 12 years ago

Flagged: the ad is very annoying, plus the title is totally misleading (read as time to live, as many others)

dang2• 12 years ago

If you flag something, please don't also comment that you did.

http://ycombinator.com/newsguidelines.html

The article itself is a good one for HN, as indicated by the fine comments at the top of this thread.

ecesena2• 12 years ago

Thanks, and sorry, I missed that point. My objective was not to shout "hey I flagged" but propose some changes, that have been done. For what it matters, I unflagged it now.

Fifty Years of Transistor-Transistor Logic

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