Microchips That Shook the World (2009)

https://spectrum.ieee.org/tech-history/silicon-revolution/25-microchips-that-shook-the-world

by jonbaer • 6 years ago

59 24 6 years ago

spectrum.ieee.org

It's a good list, but, sigh, "key innovation, a circuitry trick called address multiplexing" -- for anyone "skilled in the art", this isn't innovation. It's an OBVIOUS way to deal with the pin limitation.

I posit that much of what we herald as "innovation" is just what you'd naturally come up with if you work on the problem long and hard enough.

artemonster• 6 years ago

Don‘t be that person, don‘t diminish previous achievements. You, with all your arrogance, still stand on the shoulders of giants. These „innovations“ are so frickin obvious and easy because you‘ve learned about them. Inventing them for the first time is 100x harder.

bluu00• 6 years ago

Kalm. Read the thread again. Who was more arrogrant?

He has some point tho.

LeifCarrotson• 6 years ago

I don't think OP was trying to be arrogant, I expect he would have diminished his own previous achievements as well.

I've had several projects that resulted in "patent pending" applications that I've had to review. It's frustrating to talk to sales and legal folks who want to sell an innovation as if it were some culinary experience for which we've got not only a secret sauce recipe but also world-class chef skills, when I know it wasn't particularly difficult: I just stood in the kitchen with supermarket ingredients, an average palette, and tried variations until it tasted the way I wanted it to.

I'm not cooking, I'm building automation equipment, but the fact that you couldn't buy something off the shelf to do a particular task before my efforts was primarily because the application wasn't common enough yet to make it a commodity, not that it was an insurmountable obstacle that I miraculously overcame.

kjs3• 6 years ago

For every innovation, there's will come a pack of naysayers without the talent, tenacity or luck to accomplish the same feat who will claim (usually long after the fact) that 'anyone' (usually implying themself) could have come up with said innovation. It's a good sieve to weed out folks not worth wasting time on.

kens2• 6 years ago

If you do address multiplexing the obvious way, it will slow down your memory cycle since you need two steps to load the address. The solution in the MK4096 memory chip was you first load the row address and the memory chip starts accessing the row of 64 bits. While that is happening, you load in the column address. That should be loaded at about the same time the 64 bits are ready to select. The column address then selects the one bit you want out of the 64-bit row.

The result is that you can avoid the speed penalty of address multiplexing, but it requires careful timing, latching, and two separate internal clocks.

FullyFunctional4• 6 years ago

How is that not obvious? Since per definition you _must_ latch part of what's being multiplexed, sending it when it hasn't changed would be kind of silly.

trhway• 6 years ago

i think you're mixing innovation and invention.

just what you'd naturally come up with if you work on the problem long and hard enough

yes, there are systematic approaches to generate inventions (especially if we use the truly low bar of "patentable" :). Even more, if you look at Einstein and the rest of 20th century science following his methodology, i think there is a systematic approach to making discoveries too. And i suspect that "epiphanies" happen mostly to somebody who worked on the problem long and hard enough. Even "epiphaneous" graphene discovery i think was really a result of the long chain of senselessly looking experiments like levitating a frog (an Ig Noble winner).

dragontamer3• 6 years ago

I posit that much of what we herald as "innovation" is just what you'd naturally come up with if you work on the problem long and hard enough.

It was the invention of tri-state logic that made address multiplexing easy to do.

Yeah, with tri-state logic (high voltage, low-voltage, and high-impedance state), its easy to implement. But before the high-impedance state was formalized, its less obvious how you're supposed to hook up multiple chips onto a single address + data bus.

Someone had to invent "Chip Select", as well as how the transistors, voltages, and currents flow under such conditions. Its certainly easy to "reinvent" after you've been introduced to the concept, but it probably wasn't easy to think up first.

kens2• 6 years ago

As a historical note, there are several approaches for hooking multiple devices to a bus before TRI-STATE® logic. Early IBM mainframes (such as the IBM 1401) used AND-OR gates for the bus. Each signal onto the bus was gated by an AND gate to control who was talking to the bus, and the AND gates were connected by wired-OR.

Another common approach was the open-collector bus, for example in the Xerox Alto. The gates connected to the bus could pull the bus low but not high. Pull-up resistors pulled the bus high. In some cases, multiple devices would deliberately talk to the bus at the same time, OR-ing together their values. The downside of an open-collector bus is it's relatively slow to transition high, since you have a low-current resistor pulling it high. Tri-state drivers, on the other hand, can provide a solid current both high and low.

(TRI-STATE is a registered trademark of National Semiconductor, interestingly enough.)

FullyFunctional4• 6 years ago

Aren't you mixing two things? TRISTATE was required to hook up multiple chips _data_ lines, yes, but not the address lines, which are input-only. If the innovation was sharing the data bus, then, sure, that would make more sense.

FWIW, even the 4004 (1971, predating the MK4096 by three years) used multiplexing and I'm sure it was a known approach prior to that.

TheSpiceIsLife• 6 years ago

Constrained solution space.

pinewurst• 6 years ago

There's also their "Hall of Fame" updated until they stopped in 2019

https://spectrum.ieee.org/static/chip-hall-of-fame

jeffbee• 6 years ago

Imagine refusing to raise the pay of the inventor of the integrated op-amp.

rcarmo• 6 years ago

The 555 tops the list, as usual. I have a sweet spot for it, since it was the first IC I was allowed to use for my own projects-even if I blame it for ushering in an entire era of blinkenlights...

filterfish• 6 years ago

I blew the top of a 555 once! I still remember peering into the whole in the top where I could still see bits of the die left. Most of it was gone! I never worked out what happened and my teacher couldn't shed any light on it either.

Fortunately the ejected packaging didn't hit me in the eye!

taneq• 6 years ago

I was just thinking earlier (after seeing a tutorial on "how to blink a laser with an Arduino", spoiler alert, it's the same as blinking any other light source!) that we need a dev board that just has a 555 on it.

Microchips That Shook the World (2009)

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