Outdated CPUs

[TheNewGuy]

Hello ETO,
I have a bunch of old CPUs I've been collecting from junked computers that I've been taking to the recycling centers. I have them on my desk, and they are giving me these googley eyes!

To name a few:
Intel Celeron
Intel Pentium III
AMD Athlon 1100

I just wish I could use them for something! Maybe a small embedded system? I'm guessing though they would require a lot of supporting circuitry to get them to do anything though.

EDIT: Thanks to everyone who responded!

 

[dougy83]

They will need a lot of support circuitry, and well-designed [multilayer] PCBs... The best and easiest way to make use of them is to obtain a matching motherboard, e.g. from the computer that you got the CPUs from. With the addition of a power supply, boot drive and memory you then have a headless faux-embedded computer.

IMHO they're not of any value or use without the rest of the PC.

 

[Ian Rogers]

Pentium chips are nearly large enough to use as coasters

 

[TheNewGuy]

They will need a lot of support circuitry, and well-designed [multilayer] PCBs... The best and easiest way to make use of them is to obtain a matching motherboard, e.g. from the computer that you got the CPUs from. With the addition of a power supply, boot drive and memory you then have a headless faux-embedded computer.

IMHO they're not of any value or use without the rest of the PC.

I've done headless Linux servers before with old comps (It's a lot of fun), I wanted to see if I could make use of the CPU only.

Pentium chips are nearly large enough to use as coasters

Ha ha, seriously!

 

[Ian Rogers]

I was being serious..... These things have 370 / 479 pins... The support chips provide the interface to do anything useful... They need POST chips as the only thing they do is process.

They don't even have memory... I seriously can't see ( outside of the motherboard ) what you could use one for...

 

[picbits]

You could hook them up to a high current PSU and use them for novelty heaters ?

 

[MrAl]

Hi,

Seriously a chip like the 386 or 486 could probably be used for something else, but it's not an easy task to interface with the outside world because it needs so much to go along with it. It's like designing your own mother board. It can be done and i've actually done this with several chips, but they were somewhat less complicated, like the 8080 and the Zilog Z80.

Even those chips required a clock generator, static RAM, and a ROM where the ROM has to at the least be able to allow you to load code via another computer (often called boot loader code or something like that). And also to use it with anything you need to build an I/O port min probably the 74LS138 or equivalent, and a few logic gates like 74LS00 and 74LS02 or something like that.

The main task is to design a decoder to be able to automatically switch between ROM and RAM and I/O. That way your code can access either when needed. The boot loader code can be quite simple where you read a port and assume serial data, then send that data from another computer. That allows you to quickly test code using the RAM for the instruction code.

The 8080 board was about 6x8 inches, and the Z80 board was about 4x6 inches including all the support chips. The 8080 was built with single step capability but the Z80 was built without that feature.

What you can do if you want to research this a bit more is to download the data sheet for the chip you want to use, and study the pinout carefully to learn what each pin is used for. You then decide how to handle the signals that are expected from those pins. You also have to download the software manual for the intended chip, and study the instructions to find out how to design the boot loader code. You also have to be able to program a ROM (EEPROM, UVPROM, whatever) chip with the boot loader code so when you power up the 'computer' knows enough to look at one of the ports and wait for new code to come in, and load the RAM with that code.

So it takes a bit of doing to get up and running. I think you would be able to do this but it would take some time. A faster approach is to look at some of the micro controller chips out there and use one of those instead. They are interesting and have a lot of capabilities in one little package and are not that expensive. Takes a little time to learn how to code one but not too long.

Funny, my Z80 board was used as a controller, which now can be done with a micro controller.

Way back when i assisted in the design of computers that were made from discrete IC chips like TTL and static memory chips. So the CPU for the system took up one huge board just for that (maybe 10 x 12 inches). That's a real pain compared with what we have today.

 

[schmitt trigger]

Me...I would put them in a nice display box. These things will become collectibles in a few years.

Several years ago, an acquaintance that had worked for Western Electric had an old 300B vacuum tube laying around. These were already sought after by audiophiles, but this tube was defective.
So he made a nice wood box with a glass window, with green velvet on the inside....very nice.
He sold that recently for over 900 Us dlls.

 

[tcmtech]

What do you mean outdated?

I am hoping that our next 'new' computer our company main office sends us has something that modern in it!

Seriously our last new computer was 6 years old when it showed up and needed a complete software overhaul before we could use it.

 

[ronsimpson]

What do you mean outdated?

I am hoping that our next 'new' computer our company main office sends us has something that modern in it!

Seriously our last new computer was 6 years old when it showed up and needed a complete software overhaul before we could use it.

When California "recycles" computers they get sent to India. Then India retires their computers they go to North Dakota.

 

[TheNewGuy]

I was being serious..... These things have 370 / 479 pins... The support chips provide the interface to do anything useful... They need POST chips as the only thing they do is process.

They don't even have memory... I seriously can't see ( outside of the motherboard ) what you could use one for...

Considering what I could use them for...it's not worth it. I should have kept the motherboard if I wanted to use them for anything like you said.

Me...I would put them in a nice display box. These things will become collectibles in a few years.

Several years ago, an acquaintance that had worked for Western Electric had an old 300B vacuum tube laying around. These were already sought after by audiophiles, but this tube was defective.
So he made a nice wood box with a glass window, with green velvet on the inside....very nice.
He sold that recently for over 900 Us dlls.

This is what I'll probably end up doing with them...collect them and maybe make a profit off them one day.

You could hook them up to a high current PSU and use them for novelty heaters ?

I hope I never get that desperate for heat...haha.

Hi,

Seriously a chip like the 386 or 486 could probably be used for something else, but it's not an easy task to interface with the outside world because it needs so much to go along with it. It's like designing your own mother board. It can be done and i've actually done this with several chips, but they were somewhat less complicated, like the 8080 and the Zilog Z80.

Even those chips required a clock generator, static RAM, and a ROM where the ROM has to at the least be able to allow you to load code via another computer (often called boot loader code or something like that). And also to use it with anything you need to build an I/O port min probably the 74LS138 or equivalent, and a few logic gates like 74LS00 and 74LS02 or something like that.

The main task is to design a decoder to be able to automatically switch between ROM and RAM and I/O. That way your code can access either when needed. The boot loader code can be quite simple where you read a port and assume serial data, then send that data from another computer. That allows you to quickly test code using the RAM for the instruction code.

The 8080 board was about 6x8 inches, and the Z80 board was about 4x6 inches including all the support chips. The 8080 was built with single step capability but the Z80 was built without that feature.

What you can do if you want to research this a bit more is to download the data sheet for the chip you want to use, and study the pinout carefully to learn what each pin is used for. You then decide how to handle the signals that are expected from those pins. You also have to download the software manual for the intended chip, and study the instructions to find out how to design the boot loader code. You also have to be able to program a ROM (EEPROM, UVPROM, whatever) chip with the boot loader code so when you power up the 'computer' knows enough to look at one of the ports and wait for new code to come in, and load the RAM with that code.

So it takes a bit of doing to get up and running. I think you would be able to do this but it would take some time. A faster approach is to look at some of the micro controller chips out there and use one of those instead. They are interesting and have a lot of capabilities in one little package and are not that expensive. Takes a little time to learn how to code one but not too long.

Funny, my Z80 board was used as a controller, which now can be done with a micro controller.

Way back when i assisted in the design of computers that were made from discrete IC chips like TTL and static memory chips. So the CPU for the system took up one huge board just for that (maybe 10 x 12 inches). That's a real pain compared with what we have today.

Thank you for all the info! I think I might do what you mentioned regarding the micro controller chips. I want to study how everything works a bit more.

 

[TheNewGuy]

What do you mean outdated?

I am hoping that our next 'new' computer our company main office sends us has something that modern in it!

Seriously our last new computer was 6 years old when it showed up and needed a complete software overhaul before we could use it.

If you don't mind me asking, what is the oldest computer that you guys use regularly? Why are you guys using such old technology?

When California "recycles" computers they get sent to India. Then India retires their computers they go to North Dakota.

You can't be serious? Why do we send them to India?

 

[ronsimpson]

Sorry I was trying to insult N.D. and may have insulted India by mistake.

Computer hazardous waist gets sent to places with different hazardous waist policies. I disposed of several truck loads of CRT monitors and they probably were sent to a faraway place where children disassembled them with hammers to get gold, silver, and cadmium. Some of the monitors went to Sawyer North Dakota along with some x286 computers. Sorry TCMTech I should have updated Windows 95 first.

 

[TheNewGuy]

I'm a bit curious, what programming language do most microcontrollers use? I've read that you can use C. Last semester I finished a class on C++, and this semester I am taking a class on C. I'm thinking this class could come in handy when I go to program microcontrollers, right?

 

[dougy83]

I'm a bit curious, what programming language do most microcontrollers use? I've read that you can use C. Last semester I finished a class on C++, and this semester I am taking a class on C. I'm thinking this class could come in handy when I go to program microcontrollers, right?

C is most common and is applicable for use on small limited-resource uCs as well as larger, more capable uCs. C++ is also common for the more capable uCs.

 

[MrAl]

Hi again,


The oldest computer i ever used was the 8080 based board that i built a long long time ago. The one after that was the Sinclair ZX80, but the one i used the most (over 10 years or so) was the TRS80 (often called the "Trash-80") and that was Z80 based too. Nice thing about the TRS80 was that it was completely understandable from all the hardware to all the software including the operating system that came with it. It was so understandable that i was able to tweek the operating system itself when it became outdated around 1988...the date of the files would not accept anything over 1987 because it only used three bits for the year, so which allowed only the years 1980 to 1987...ha ha. But even with it's single color green screen, i used it for years...even though it only had two floppy drives (180k bytes each) and no hard drive...the hard drive for that thing was about 400 dollars (USD) for about 40 megabytes...ha ha.

I since then moved on to an 8088 based computer with 16 color monitor, then to an 80386 computer which i loved, then to 80486, then to a pentium based computer, then to a dual core system, then to a quad core system, then finally to an 8 core system which i use today. But dont forget about the Android tablets, they are pretty neat too and make portability a little simpler and more economical than a laptop.

Yes you can use C to program a micro controller chip, or BASIC, or Assembler. I use Assembler mostly as it makes me feel more in touch with the hardware.

 

[TheNewGuy]

C is most common and is applicable for use on small limited-resource uCs as well as larger, more capable uCs. C++ is also common for the more capable uCs.

Even C++? That is awesome! In my C++ class, we were told that C++ is resource heavy due to it being object oriented. So it makes sense when you say only the more capable microcontrollers.

Hi again,


The oldest computer i ever used was the 8080 based board that i built a long long time ago. The one after that was the Sinclair ZX80, but the one i used the most (over 10 years or so) was the TRS80 (often called the "Trash-80") and that was Z80 based too. Nice thing about the TRS80 was that it was completely understandable from all the hardware to all the software including the operating system that came with it. It was so understandable that i was able to tweek the operating system itself when it became outdated around 1988...the date of the files would not accept anything over 1987 because it only used three bits for the year, so which allowed only the years 1980 to 1987...ha ha. But even with it's single color green screen, i used it for years...even though it only had two floppy drives (180k bytes each) and no hard drive...the hard drive for that thing was about 400 dollars (USD) for about 40 megabytes...ha ha.

I since then moved on to an 8088 based computer with 16 color monitor, then to an 80386 computer which i loved, then to 80486, then to a pentium based computer, then to a dual core system, then to a quad core system, then finally to an 8 core system which i use today. But dont forget about the Android tablets, they are pretty neat too and make portability a little simpler and more economical than a laptop.

Yes you can use C to program a micro controller chip, or BASIC, or Assembler. I use Assembler mostly as it makes me feel more in touch with the hardware.

It's pretty cool to see the clock speeds than one can get in microprocessors today compared to the older ones. I think it is pretty cool. I bet that $400 hard drive you mentioned was huge in size as well.

 

[fernando_g]

The New York Times had once an investigation of "recycling centers" in poor countries.

Many metals are recycled, which in itself, is a good thing...the bad thing is the job conditions and hazards in those places.

The other bad thing is that many ICs are removed, cleaned, and sold to the gray market...to unsuspecting buyers.

 

[elfcurry]

If you don't mind me asking, what is the oldest computer that you guys use regularly? Why are you guys using such old technology?

Not in regular use but the simplest I ever worked on was a 4-bit Hitachi HMCS2.

It was a 4 bit processor though the instructions were 10 bits wide. This was 1982 and the company I worked for tendered for a contract to make a cheap, low-sensitivity digital radiation monitor for the government to be used after a nuclear attack. It became the PDRM82 - Google it.

This chip was chosen because it could directly drive an LCD and had just enough guts to do the processing necessary to scale the input from one of several different sensitivity grades of GM tube. And it was cheap. The pulse train from the small basic GM tube went through an 8 bit prescaler before going to the chip.

From a 'software' pov it was excruciating! A very basic instruction set, just crude assembler and no tools to speak of.

RAM consisted of a notional block of 160 locations I think, addressed with X and Y coordinates.
To get a 4 bit nibble of data into the accumulator it took three instructions:
1. load x-reg with part of RAM address
2. load y-reg with remainder of address
3. load data from indicated address into accumulator.

But it was exciting too and we got the contract to make 80,000 of them!

 

[tcmtech]

If you don't mind me asking, what is the oldest computer that you guys use regularly? Why are you guys using such old technology?

Because we spend so much money on being safe and documenting it there is no budget left to do work with anything modern.

Honestly I don't know why we run such old computers other than we get the hand me downs from the main offices once they have become to old and glitchy for the executives to use.

Our most recent computer at lest got us into the world of windows XP now! Granted I still had to install service pack 3 myself after we got it.