This was a very interesting read. I have read a bit about the 4004 before so I knew it was strange. But the level of obscurity is mind-blowing. Now I just got the urge to see how well I would be able to make a CPU with the same transistor count. It's not that much fewer than a 6502. 8 bit would make it so much easier to program.
Wow. And I thought modern NetBSD on a 15 MHz m68030 with a 16 bit memory bus and 10 megabytes of RAM is slow. This is crazy!
It illustrates a point I've explained to many people over the years: once computers started coming with persistent storage, open address spaces and MMUs towards the late '80s and early '90s, we basically arrived at modern computing. An Amiga 3000 or i80486 computer can run the same things as a modern computer. Sure, we have ways to run things orders of magnitude faster, and sure, we now have things that didn't exist then (like GPUs that can run code), but there's no functional difference between those machines and new ones.
I love that Dmitry shows how loosely "functional" can be defined :)
That's basically the concept of Turing Completeness. Any Turing complete system can run anything. It may be very slow, but it will run. ChatGPT could run on a 4004, all you need is time.
I don’t know if this was a thing in America, but in USSR in the 70s and 80s it was very popular to play chess-by-correspondence. You would literally snail-mail letters back-and-forth with your move. Games would last months or years. It added an extra challenge to chess because by the time you got a response, you might have forgotten what strategy you had had.
This project is basically Linux-by-correspondence. The challenge is here too. By the time the command produces an output, you might have forgotten why you ran it.
There was something called Agora (https://en.wikipedia.org/wiki/Agora_(web_browser)) which was sort of an email/http proxy. You could browse the web via. email and set "GET", "POST" etc. commands. It was my first exposure to the web.
I installed Windows 95 on an Amiga 3000 with a 25 MHz m68030 via floppy to see if DMF formatted disks would work and to play around. By the time it finished, I had forgotten what I wanted to try out.
Wow this was not a cheap project! Thanks Ebay collectors.
Also probably the only time I'd have gone for an LCD over a VFD. If you're running a multi-year long compile, it'll probably be burned in to hell by the end.
For the video, i wanted a laptop with a real serial port (no usb). This one fit the bill and was $20 on eBay. Windows 2000 is the prettiest windows IMHO, so that’s what I installed for the demo video.
That's kind of insulting honestly. Getting Linux to run on an i4004 is bona fide engineering. More real than engineering that we're paid to do most times. Looking at the list of Ig Nobel Prize winners it sounds like The Onion but not funny.
Very impressive work, but most of the work has been necessary because Intel 4004 was not really the first microprocessor, this was just BS propaganda used by Intel to push back by one year the date of the launch of the first microprocessor, to 1971.
The first true (civilian) microprocessor was Intel 8008, in 1972.
Intel 8008 was a monolithic implementation, i.e. in a single PMOS integrated circuit, of the processor of Datapoint 2200, therefore it deserves the name "microprocessor".
The processor of Datapoint 2200 had an ugly architecture, but there is no doubt that it was a general-purpose CPU and traces of its ISA remain present in the latest Intel and AMD CPUs.
On the other hand, the set of chips that included Intel 4004 was not intended for the implementation of a general-purpose computer, but it was intended just for the implementation of a classic desktop calculator, not even a programmable desktop calculator.
This is the reason for the many quirks of Intel 4004, e.g. the lack of instructions for the logic operations, and many others that have increased the amount of work required for implementing a MIPS emulator suitable for running Linux.
Even if Intel 4004 was intended for a restricted application, after Intel has offered to sell it to anyone, there have been many who have succeeded to use it in various creative ways for implementing microcontrollers for the automation of diverse industrial processes, saving some money or some space over a TTL implementation.
In the early days of the electronics industry it was very normal to find ways to use integrated circuits for purposes very different from those for which the circuits had been designed. Such applications do not make Intel 4004 a true microcontroller or microprocessor. Very soon many other companies, and later also Intel, have begun to produce true microcontrollers, designed for this purpose, either 4-bit or 8-bit MCUs, then Intel 4004 has no longer been used for new designs.
I'm glad to see the Datapoint 2200 is getting attention, but by reasonable definitions of "microprocessor", the Intel 4004 was first, the Texas Instruments TMX 1795 was second, and the Intel 8008 was third. It seems like you're ruling out the 4004 on the basis of "intent" since it was designed for a calculator. But my view is that the 4004 is a programmable, general-purpose CPU-on-a-chip, so it's a microprocessor. Much as I'd like to rule out the 4004 as the first microprocessor, I don't see any justifiable grounds to do this.
Intel's real innovation—the thing that made the microprocessor important—was creating the microprocessor as a product category. Selling a low-cost general-purpose processor chip to anyone who wanted it is what created the modern computer industry. By this perspective, too, the 4004 was the first microprocessor, creating the category.
Your argument is that because the 4004 was built to power a calculator that disqualifies it as a microprocessor? Independent of the actual nature of the 4004 itself and its potential applications beyond its first intended use? Can’t see how that makes sense at all.
Your statement about Intel 'pushing back' the date to 1971 also makes little sense given Intel advertised [1] the 4004 as a CPU in Electronic News in Nov 1971.
No kidding about unusual uses of ICs. Not related to microprocessors, but I have an old analog triple conversion HF receiver (Eddystone EC958/3 for what it's worth) that uses a TTL IC in an analog circuit! I'd have to look at the schematic again, I think it's a multi-stage counter, but basically what it uses it for is to generate a comb shaped spectrum, one "spike" of which can then be picked up by an analog circuit and locked to, to generate precisely spaced tuning steps for the high stability tuning.
I didn't know the guy but he clearly knows what he's doing, it's unbelievably entertaining to read the details of achieving an impossible task with the most underpowered tool possible.
I mean, it's fun and interesting bullshit that cheats a lot. I'm sure that you could emulate a MIPS using a one-bit processor like the MC14500[0] with enough supporting hardware, real or virtual. Looking forward to it, Dimitry.
At some point you will just need to offload the actual "processing" part to some nice old chap named Dave who has himself an abacus, and every now and then you send him a letter and he moves some stones and sends a letter back with the result.
Windows ran on a similar MIPS machine (Microsoft jazz). The issue is emulating scsi. I think I’d need a lot more rom space to do that. Scam is messy and hard.
The alternative is to find the Windows MIPS DDK and build a paravirtualized disk driver for it like I did for Linux. That would make it more doable.
> But for the one I'll have hanging in my office, I have loftier goals. With swap enabled, the kernel sources can actually be built right on-device. It will take some number of years. The partition where the kernel lives is /dev/pvd2 and is mounted under /boot. The device can build its own kernel from source, copy it to /boot/vmlinux, and reboot into it. If power is interrupted, thanks to ext4, it will reboot, recover the filesystem damage from the journal, and restart the compilation process. That is my plan, at least.
One, it reminds me of that "worlds longest song" or somesuch thing, where they play a note every 10 years.
The other is just a picture of someone, asleep at their desk, a pile of calendars with days checked off tossed to the side, random unwashed mugs and such all dimly lit by a desk lamp and see the `$ make linux` finally return to an new, unassuming `$` prompt. Like Neo in the Matrix.
Yes. I have an emulator of this board (it is in the downloads too) which is much faster than the real thing. It shows how much realtime is needed to get to the current state. Doing a build in it will answer the question unequivocally.
This was a very interesting read. I have read a bit about the 4004 before so I knew it was strange. But the level of obscurity is mind-blowing. Now I just got the urge to see how well I would be able to make a CPU with the same transistor count. It's not that much fewer than a 6502. 8 bit would make it so much easier to program.
Thanks for documenting your work so well!
Wow. And I thought modern NetBSD on a 15 MHz m68030 with a 16 bit memory bus and 10 megabytes of RAM is slow. This is crazy!
It illustrates a point I've explained to many people over the years: once computers started coming with persistent storage, open address spaces and MMUs towards the late '80s and early '90s, we basically arrived at modern computing. An Amiga 3000 or i80486 computer can run the same things as a modern computer. Sure, we have ways to run things orders of magnitude faster, and sure, we now have things that didn't exist then (like GPUs that can run code), but there's no functional difference between those machines and new ones.
I love that Dmitry shows how loosely "functional" can be defined :)
That's basically the concept of Turing Completeness. Any Turing complete system can run anything. It may be very slow, but it will run. ChatGPT could run on a 4004, all you need is time.
https://cs.stackexchange.com/a/60978
And a gargantuan amount of RAM.
I don’t know if this was a thing in America, but in USSR in the 70s and 80s it was very popular to play chess-by-correspondence. You would literally snail-mail letters back-and-forth with your move. Games would last months or years. It added an extra challenge to chess because by the time you got a response, you might have forgotten what strategy you had had.
This project is basically Linux-by-correspondence. The challenge is here too. By the time the command produces an output, you might have forgotten why you ran it.
There was something called Agora (https://en.wikipedia.org/wiki/Agora_(web_browser)) which was sort of an email/http proxy. You could browse the web via. email and set "GET", "POST" etc. commands. It was my first exposure to the web.
It sounds very similar to what you mentioned.
I installed Windows 95 on an Amiga 3000 with a 25 MHz m68030 via floppy to see if DMF formatted disks would work and to play around. By the time it finished, I had forgotten what I wanted to try out.
I love giving the AVR example when people ask if something can run on an underpowered machine, now I have a new example to link.
Considering the frequencies and wattage I wonder how RF it spits out and what is detectable and decodable on the waterfall of a SDR.
By the way still reading through it, but at the time of this comment I see the word "soubroutine" which is probably a misspelling.
Fixed the typo. Thanks
Wow this was not a cheap project! Thanks Ebay collectors.
Also probably the only time I'd have gone for an LCD over a VFD. If you're running a multi-year long compile, it'll probably be burned in to hell by the end.
oof. amazing.
…you can see in the high PC bits what's currently executing!
P.S.: Still loads the kernel faster than a virtual ISO on a server's shitty IPMI over the internet ;D
While it boots, you can look at LEDs and map them to kernel function easily by running “nm” on vmlinux.
Also, when in user space, you can tell between the main binary (way below 0x01000000) and shared libraries (loaded high near 0x77000000)
The video took 9 days to film. 4 hours per emulated second.
Also I wonder why he's using Windows 95?
Sorry for the nitpick, but the laptop in the video looks like Windows 2000
The best Windows imo
True
Windows 2000
For the video, i wanted a laptop with a real serial port (no usb). This one fit the bill and was $20 on eBay. Windows 2000 is the prettiest windows IMHO, so that’s what I installed for the demo video.
Virtual machine (as in the Z-machine or the JVM) worked on early micros when you couldn’t use them as compiler targets. See
https://en.wikipedia.org/wiki/SWEET16
https://en.wikipedia.org/wiki/UCSD_Pascal
There needs to be something like a Nobel Prize for this kind of thing.
Probably closest would be the Ig: https://en.wikipedia.org/wiki/Ig_Nobel_Prize
That's kind of insulting honestly. Getting Linux to run on an i4004 is bona fide engineering. More real than engineering that we're paid to do most times. Looking at the list of Ig Nobel Prize winners it sounds like The Onion but not funny.
Supposed to be, apparently.
The proof of the Turing Completeness Theorem in action. Beautiful. Boot time is ~5 days.
In the "Why MIPS?" section:
> some have shitty addressing modes necessitating that they would be slow (RISCV)
What is wrong with the RISC-V addressing modes?
Probably nothing unless you want to emulate it on severely underpowered hardware.
At first i was like "I'm pretty sure this is bullshit or some cheat used" but then i was like "Oh, its dimitry."
Impressive work, as always.
Very impressive work, but most of the work has been necessary because Intel 4004 was not really the first microprocessor, this was just BS propaganda used by Intel to push back by one year the date of the launch of the first microprocessor, to 1971.
The first true (civilian) microprocessor was Intel 8008, in 1972.
Intel 8008 was a monolithic implementation, i.e. in a single PMOS integrated circuit, of the processor of Datapoint 2200, therefore it deserves the name "microprocessor".
The processor of Datapoint 2200 had an ugly architecture, but there is no doubt that it was a general-purpose CPU and traces of its ISA remain present in the latest Intel and AMD CPUs.
On the other hand, the set of chips that included Intel 4004 was not intended for the implementation of a general-purpose computer, but it was intended just for the implementation of a classic desktop calculator, not even a programmable desktop calculator.
This is the reason for the many quirks of Intel 4004, e.g. the lack of instructions for the logic operations, and many others that have increased the amount of work required for implementing a MIPS emulator suitable for running Linux.
Even if Intel 4004 was intended for a restricted application, after Intel has offered to sell it to anyone, there have been many who have succeeded to use it in various creative ways for implementing microcontrollers for the automation of diverse industrial processes, saving some money or some space over a TTL implementation.
In the early days of the electronics industry it was very normal to find ways to use integrated circuits for purposes very different from those for which the circuits had been designed. Such applications do not make Intel 4004 a true microcontroller or microprocessor. Very soon many other companies, and later also Intel, have begun to produce true microcontrollers, designed for this purpose, either 4-bit or 8-bit MCUs, then Intel 4004 has no longer been used for new designs.
I'm glad to see the Datapoint 2200 is getting attention, but by reasonable definitions of "microprocessor", the Intel 4004 was first, the Texas Instruments TMX 1795 was second, and the Intel 8008 was third. It seems like you're ruling out the 4004 on the basis of "intent" since it was designed for a calculator. But my view is that the 4004 is a programmable, general-purpose CPU-on-a-chip, so it's a microprocessor. Much as I'd like to rule out the 4004 as the first microprocessor, I don't see any justifiable grounds to do this.
Intel's real innovation—the thing that made the microprocessor important—was creating the microprocessor as a product category. Selling a low-cost general-purpose processor chip to anyone who wanted it is what created the modern computer industry. By this perspective, too, the 4004 was the first microprocessor, creating the category.
My article in IEEE Spectrum on this subject goes into much more detail: https://spectrum.ieee.org/the-surprising-story-of-the-first-...
Your argument is that because the 4004 was built to power a calculator that disqualifies it as a microprocessor? Independent of the actual nature of the 4004 itself and its potential applications beyond its first intended use? Can’t see how that makes sense at all.
Your statement about Intel 'pushing back' the date to 1971 also makes little sense given Intel advertised [1] the 4004 as a CPU in Electronic News in Nov 1971.
[1] https://en.wikipedia.org/wiki/Intel_4004#/media/File:Intel_4...
No kidding about unusual uses of ICs. Not related to microprocessors, but I have an old analog triple conversion HF receiver (Eddystone EC958/3 for what it's worth) that uses a TTL IC in an analog circuit! I'd have to look at the schematic again, I think it's a multi-stage counter, but basically what it uses it for is to generate a comb shaped spectrum, one "spike" of which can then be picked up by an analog circuit and locked to, to generate precisely spaced tuning steps for the high stability tuning.
The naming and propaganda wouldn’t matter. I just wanted something lower-end for sure than a 6510 and an AVR. 4004 is that
Is this the oldest piece of hardware that's ever run Linux, I'm left wondering?
It surely is
Glad to see someone besides me posting this whenever 4004 history-rewriting comes up.
I didn't know the guy but he clearly knows what he's doing, it's unbelievably entertaining to read the details of achieving an impossible task with the most underpowered tool possible.
I mean, it's fun and interesting bullshit that cheats a lot. I'm sure that you could emulate a MIPS using a one-bit processor like the MC14500[0] with enough supporting hardware, real or virtual. Looking forward to it, Dimitry.
[0] https://en.wikipedia.org/wiki/Motorola_MC14500B
We need this for the Usagi Electric vacuum tube computer.
I’ll work on setting a new lower record every ten years or so. My guess at the next three steps: one bit controller, transistors only, vacuum tubes.
At some point you will just need to offload the actual "processing" part to some nice old chap named Dave who has himself an abacus, and every now and then you send him a letter and he moves some stones and sends a letter back with the result.
CPU-by-correspondence!
This is absolutely insane - hats off to you. To say it's impressive it's like to say nothing.
Mission impossible — do it with Windows!
Windows ran on a similar MIPS machine (Microsoft jazz). The issue is emulating scsi. I think I’d need a lot more rom space to do that. Scam is messy and hard.
The alternative is to find the Windows MIPS DDK and build a paravirtualized disk driver for it like I did for Linux. That would make it more doable.
> But for the one I'll have hanging in my office, I have loftier goals. With swap enabled, the kernel sources can actually be built right on-device. It will take some number of years. The partition where the kernel lives is /dev/pvd2 and is mounted under /boot. The device can build its own kernel from source, copy it to /boot/vmlinux, and reboot into it. If power is interrupted, thanks to ext4, it will reboot, recover the filesystem damage from the journal, and restart the compilation process. That is my plan, at least.
I have two visions of this.
One, it reminds me of that "worlds longest song" or somesuch thing, where they play a note every 10 years.
The other is just a picture of someone, asleep at their desk, a pile of calendars with days checked off tossed to the side, random unwashed mugs and such all dimly lit by a desk lamp and see the `$ make linux` finally return to an new, unassuming `$` prompt. Like Neo in the Matrix.
I like the second version!
I wonder of you can calculate when it will finish by counting the instructions and then pin the date it will finish and stream the completion.
Yes. I have an emulator of this board (it is in the downloads too) which is much faster than the real thing. It shows how much realtime is needed to get to the current state. Doing a build in it will answer the question unequivocally.
Update us please!!
Ars Longa, Vita Brevis
I’d assume you’d have at least a few bit flips occur in the process.
Very large-process DRAM with frequent refreshing, in ceramic cases. It might last long enough without flips