2

I have this question. Since microprocessors were first made, the technology has developed very much. I'm asking this because i would like to try to make a simple microprocessor, something like Intel 4004. I know the files for the Intel 4004 are available online.

So, how where the first made microprocessors made, like the Intel 4004, what machines they used to built them, and can an ordinary guy try to make one?

Anindo Ghosh
  • 50,188
  • 8
  • 103
  • 200
ThisGuy
  • 51
  • 2
  • 4
    Anytime someone tells me they'd like to build their own processor from scratch, I always urge these people to look into FPGAs. Building a processor with discrete components (not ASIC) does not provide a much better understanding than designing HW with an FPGA. At most in the former case, the advantage is you'll memorize how to construct logic gates from scratch and understand the nuances of transistors. FPGAs however allow one to focus solely on the logic. – Nick Williams Jul 24 '13 at 14:28
  • @TeodoroDias If you are really dedicated, Instructable's member: Teslaling constructed a 555 Timer with discrete components. This is about as low-level and as elaborate as you could attempt to go: http://www.instructables.com/id/Build-Your-Own-555-Timer/ – Nick Williams Jul 24 '13 at 15:27
  • If you're really determined to do this, also look at pjc50's answer in the question he linked above. It links to a hack-a-day article about someone who did manage to build a simple IC by hand after 2 years of effort. – Dan Is Fiddling By Firelight Jul 24 '13 at 16:06
  • seconding @NickWilliams the headache from debugging irrelevant (to the understanding of cpu's) issues when wire wrapping even simple CPU's based on discrete components isn't worth it. Trying to implement a CPU from scratch on a fpga (dev boards with enough logic units to implement a 386 are available for $100 or less) is much more rewarding. – crasic Jul 26 '13 at 23:14

2 Answers2

7

How were the first microprocessors made? ... can an ordinary guy try to make one?

An ordinary person doesn't have the resources that were available to a business like Intel in 1971.

It would be like filling your garage with this

A lump of iron ore

And from that constructing this 1971 artifact using a budget of $500 and one person's evenings and weekends.

enter image description here

However, you can construct a CPU from basic logic ICs - Example

See this answer to the Q of which this is pretty much a duplicate.

It took Jeri Ellsworth 2 years to make an inverter (two FETs) about the size of a quarter. Most of that time was working out a process simple enough that she could use it at home. So I guess she could probably go on and eventually produce a logic gate a day using that method. So that would take maybe 10 years (weekends off and a couple of vacations a year) to make enough gates to construct something like an Intel 4004. The result would perhaps be a "chip" the size of a large car (if not a small house).

Some other people are working towards a smaller scale, more integrated, and less hand-hewn process - but it seems they've been working for a couple of years and don't have any working devices yet. They do have some impressive small-scale artifacts though. I'd guess they may still be many years away from process that is both affordable and usable at home.

Community
  • 1
RedGrittyBrick
  • 14,602
  • 5
  • 37
  • 77
6

Well since all microprocessors are made from transistors, you will essentially be making many transistors (depeding on how in depth you want to get). Look here for transistor construction. The Intel 4004 had 2300 transistors while modern upper end CPU's have over a billion transistors. I am assuming you don't really want to go through the chemical/doping side of creating a processor, but more or less the logic side. This guide is a very good introduction to 8-bit processing and creating a simple 8-bit computer. Lastly, this page walks you through an even more primitive CPU design. Hopefully, that is enough info to help get you started.

Josh
  • 459
  • 1
  • 5
  • 13
  • No, i really would like to go through the chemical/doping side of creating a processor. I have already searched, but couldn't find any information how to make it. If you could help, that would be wonderfull – ThisGuy Jul 24 '13 at 15:08
  • 1
    @TeodoroDias It is simply not reasonable for you to expect to fabricate your own integrated circuit, even just a handful of transistors. You would probably require a budget around one million $US to even begin. The kind people here are trying to politely tell you that you are out of your mind to even consider it. – Joe Hass Jul 24 '13 at 15:33
  • If speed wasn't an issue, I wonder how many chips would be needed if one didn't mind some of them being rather large ROMs (flash or EPROM)? I would guess surprisingly few. Instead of using a program counter, have each "instruction" form the address of the next instruction by taking some bits of the just-executed instruction, some bits from an addressable latch, and some bits from various inputs. That's the principle used by the Apple Disk II controller, and it makes things really simple. – supercat Jul 24 '13 at 15:50
  • Well you could go even farther back in history and use relays or possibly vacuum tubes (don't know how hard they would be to make) as switches instead of transistors to avoid fabrication difficulties. – Dan Is Fiddling By Firelight Jul 24 '13 at 15:57
  • @ThisGuy, There are lots of nasty nasty chemicals involved in semiconductor processing. If you were my neighbor and I found out you were trying to do this at home, I would call the fire department hazardous materials team as fast as I could. – The Photon Jul 24 '13 at 16:02
  • @JoeHass , well for all we know OP could be a bored retired billionaire and blowing a few million on DIY building a home fab setup is just the project he is looking for. – crasic Jul 26 '13 at 23:18