How Ted Hoff invented the first microprocessor
spectrum.ieee.org
spectrum.ieee.org
Ted had a pad of conductive foam with a number of 8008 processors (a few dozen, perhaps). From time to time he would be contacted by someone in the US government asking if he had any of those chips around.
He would pick one out, carefully package it and mail it off. Since the applications were almost always very secret, he never found out what they were actually for.
(These days, you'd just write a cycle and pin accurate emulator, or design an FPGA equivalent. Not an option back then).
Of course I'm over-simplifying, but in fact, the portability of Arduino code across platforms has saved my bacon a few times during the chip shortage. There's always some overhead, such as changing a wiring harness, but it's better than being dead in the water.
I don't have a good sense if you succeed at pin-emulating a 1980s-era Z-80 or equivalent.
if all pins are held at the same electrical potential, as they would be if stuck into conductive foam, touching the same chip brings up the voltage on all pins simultaneously (or close enough) so there will be no voltage differential across the chip and thus no arcing across the silicon. no damage.
ICs of the time almost never had built-in protection for this kind of thing. modern consumer computer components like RAM sticks for example, do. it's hard to damage those with static electricity shocks even if you try.
I still have a habit of touching likely grounds from time to time whenever I'm in a lab.
Me too, it's such an ingrained habit. Before touching any "open electronics", I quickly touch the earth lug on my lab PSU, or a screw from some other (grounded) metal test equipment case. I've been doing it so long and so consistently that my hands feel "wrong" before I do that.
So much stuff has ESD protection nowadays, but some individual components at least still don't, and you only need to break one part to ruin your day (or at least some significant amount of time if you're so lucky that you can solder a replacement).
Chips are more robust today, but not 100%, and some specialized devices like laser diodes are super sensitive to ESD.
The most evil thing are those plastic mats that people put over carpet in their offices so they can roll their rolling chairs. That's like sitting on a van de graaf generator. I killed several valuable EPROMs at my first job out of school, sitting at my desk, programming, then went to touch a chip to program it, ZAP!
When chips are in circuit boards, they're much less sensitive, due to the capacitance of the board traces. It's been a long time since I worried about handling a board. Of course the cost and irreplaceability of the board figures into the risk calculation.
> Hoff never even considered patenting the microprocessor. To him the invention seemed to be obvious.
I agree with him. The microprocessor wasn’t really an invention - it was a ‘technical milestone’. Once other techniques had been mastered then it was obvious it would happen.
Credit to Hoff for spotting that a single chip CPU would work in this case but that was really about being in the right place at the right time.
On the other hand Faggin did contribute some real inventions that made the 4004 possible and actually built the thing!
"Federico Faggin was assigned to design the chip, and in nine months came up with working prototypes"... "Faggin recalled that when he began implementing the microprocessor, Hoff seemed to have lost interest in the project, and rarely interacted with him."
Kind of having a title like: "How Steve Jobs invented the first commercial personal computer" and then inside the article saying actually "Steve Wozniak designed the motherboard, power supply, video interface...."
https://sites.google.com/site/microprocessorintel4004/home/f...
His account of the events are recorded in his book Silicon https://siliconthebook.com/
http://archive.computerhistory.org/resources/text/Oral_Histo...