5 ms·

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

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 6y 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 6y ago
  Kalm. Read the thread again. Who was more arrogrant? He has some point tho.
- LeifCarrotson 6y 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.
  - bob29 6y ago
    Then why patent it instead of publishing, making yourself a well known leading expert instead of setting a landmine for the next person who does this particular task?
    - javajosh 6y ago
      Because there is a huge amount of value to extract from the artificial scarcity a patent lets you impose on the world.
- kjs3 6y 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.
kens 6y 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.
- FullyFunctional 6y 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.
  - bob29 6y ago
    SLAMS HARDBOILED EGG ON TABLE after the deed is done, everybody knows how to do it; (https://en.wikipedia.org/wiki/Egg_of_Columbus https://en.wikipedia.org/wiki/Egg_of_Columbus)
trhway 6y 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).
dragontamer 6y 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.
- kens 6y 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.)
  - dragontamer 6y ago
    > open-collector bus Ah right, and that's still used by I2C if I remember correctly (a low speed bus that's surprisingly common). I didn't know about IBM's AND-OR bus before. But now that I think of it, the open-collector bus is the exact opposite of AND-OR. Open-collector is common today because modern chips (CMOS) can sink more current than they can source. I don't know if TTL (or whatever IBM Mainframes used back then) had different characteristics which made the positive-variation more useful.
  - 6y ago
TheSpiceIsLife 6y ago
Constrained solution space.

artemonster 6y 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 6y ago
Kalm. Read the thread again. Who was more arrogrant? He has some point tho.
LeifCarrotson 6y 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.
- bob29 6y ago
  Then why patent it instead of publishing, making yourself a well known leading expert instead of setting a landmine for the next person who does this particular task?
  - javajosh 6y ago
    Because there is a huge amount of value to extract from the artificial scarcity a patent lets you impose on the world.
kjs3 6y 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.

kens 6y 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.

FullyFunctional 6y 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.
- bob29 6y ago
  SLAMS HARDBOILED EGG ON TABLE after the deed is done, everybody knows how to do it; (https://en.wikipedia.org/wiki/Egg_of_Columbus https://en.wikipedia.org/wiki/Egg_of_Columbus)

trhway 6y 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).

dragontamer 6y 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.

kens 6y 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.)
- dragontamer 6y ago
  > open-collector bus Ah right, and that's still used by I2C if I remember correctly (a low speed bus that's surprisingly common). I didn't know about IBM's AND-OR bus before. But now that I think of it, the open-collector bus is the exact opposite of AND-OR. Open-collector is common today because modern chips (CMOS) can sink more current than they can source. I don't know if TTL (or whatever IBM Mainframes used back then) had different characteristics which made the positive-variation more useful.
- 6y ago

TheSpiceIsLife 6y ago

Constrained solution space.