Intel's 4004 Microprocessor Turns 40 126
harrymcc writes "On November 15th 1971, Intel introduced the 4004 — the first single-chip microprocessor. Its offspring, needless to say, went on to change the world. But first, Intel tried using the 4004 in a bunch of products that were interesting but often unsuccessful — like a pinball machine, an electronic vote-counting machine, and Wang's first word processor. Technologizer's Benj Edwards is celebrating the anniversary with an illustrated look back at this landmark chip." Here's another nostalgic look back at V3.co.uk, and one at The Inquirer. And an anonymous reader points out another at ExtremeTech, from which comes this snippet: "Designed by the fantastically-forenamed Federico Faggin, Ted Hoff, and Stanley Mazor, the 4004 was a 4-bit, 16-pin microprocessor that operated at a mighty 740KHz — and at roughly eight clock cycles per instruction cycle (fetch, decode, execute), that means the chip was capable of executing up to 92,600 instructions per second. We can’t find the original list price, but one source indicates that it cost around $5 to manufacture, or $26 in today’s money."
Re:Interesting typo* (Score:5, Informative)
There *is* an unbroken chain of compatibility from the latest AMD processors back to the 8008, which was Intel's first 8-bit microprocessor (the design of which was actually started before the 4004 design, IIRC). So they were indeed "predecessors".
Not to mention that AMD got its start in the PC business by being an officially licensed 2nd source for Intel's 8086 chips.
Re:Interesting typo* (Score:3, Informative)
Actually, AMD processors are not 100% compatible. There are differences in behavior.
For example, everyone knows an x86 resets at FFFF:0000. But an AMD processor will throw an exception if somewhere along the line, it doesn't encounter a branch and ends up wrapping to 0000:0000. An Intel processor doesn't generate the exception. (This is because way back when, instead of putting ROM at the end of memory, designers could put it at the beginning and have the processor basically NOP its way through the 16 bytes).
It's one of the well-known well-publicized things that broke the original Xbox.
Of course, practically speaking, AMD's behaviour is probably "more correct" security wise, but Intel's is pure legacy.
Re:Who could ever need more than 740KHz? (Score:5, Informative)
There's actually a sane reason for 95kHz sampling - filtering.
Before any ADC, you need to put in an analog filter (anti-aliasing filter - basically it ensures that the signal going to the ADC is bandlimited below the Nyquist frequency).
The problem with filters is that it's very hard to get the desired characteristics (flat response in frequency band, narrow transition band) without doing a ton of work (lots of parts, etc).
Using 44kHz or 48kHz sampling, it means if you want to capture to 20kHz, your filter must "brickwall" in the 2-4kHz region between 20kHz and 22/24kHz. This is extremely hard to do, and the eng result is you usually get rolloff around 16kHz or so. Or the frequency response gets wilder and definitely not flat.
Using 96kHz or even 192kHz means the anti-aliasing filter can be much gentler and designed with more stuiable characteristics. When you can have rolloff start at 20kHz and extend all the way out to 48/96kHz, you can make some very nice filters indeed - flat from 20Hz-20kHz, very little phase distortion, etc.
The other end benefits as well - the antialiasing filter on the DAC side can be a lot nicer as well.
And of course, the more bandwidth you have to play with, it means the filters are also much cheaper and simpler (and that also means less distortion).
Re:PCs waited until 8bits came out couple years la (Score:4, Informative)
8008, 6800, and 8086
Eh? While there were a few designs using 8008 and 6800, I don't think any of them was successful; high volume commercially available PCs used Z80s (the TRS-80, the Sinclair ZX-80 and Spectrum, the MSX machines) or 6502s (Apple II, Atari, Commodore). The successor of the 6800, the excellent 6809 was used in the TRS-80 Color Computer; years later, when IBM launched their PC, they used the reduced data bus version of the 8086, that is the 8088.