What can I do with old 486 CPUs?

[Sputnik]

I have a pile of old 486DX/SX CPUs just lieing around, where could I find information as to how they work so that I could possible integrate them into a project requiring heavy mathematical calculations in comparison to a PIC16F84 that can't perform floating point arithmetic. Thanks in advance for your help.

 

[papyaki]

Hi,

Try these links to Intel site :

h**p://developer.intel.com/design/intarch/intel486/index.htm

h**p://developer.intel.com/design/intarch/intel486/docs_486.htm#Manuals

* = t

 

[eltonjohn]

Ok i played a lot with those chips .. Well right now THEY ARE OLD .. and not very powerful and on top they require too much power .They never got faster than 33 Mhz 40Mhz for the AMD .. then was the DX2 with clock doubler .. the Sx as i remember never went beyond 25Mhz.. These chips are very slow by today standards ..In order to make them work they require big memory interfaces and 32 bit data paths( 16 for the SX) ,, slow memories etc EPROMS, SRAMS and GLUE logic PALS etc .the most probematic things is that they require external interrupt controler external DMA etc .. so basically is a very much NAKED chip ..a Cygnal chip or a Avr would probably give you better results . The external memory bus is slow . 2 clock cycles .Unless you use the BURST mode .. well a lot of logic to make the state machines to track the bus . Is still a complicated chip .
If you go trough all that pain of interfacing one to a PCI o other bus you won't even get a lot of power .at most 12 MIPS ! that's all .But where you will find a lot of trouble is in getting a BIOS ( well you could use HAL ) But also the INTEL COMPILERS hard to find these days ( i have them if you need them ..though you could use GNU)
The software required to put them to work can be complex You need an assembler a LINKER a BINDER and a MAPPER to create your IMAGE .
Unfurtunatly the industry has got awat from this type of architecture so whatever you learn won't be useful in the future.
Listen one time i manage to get the BOTTOM LID of those chips so the DIE could be seen then i glued a TACK at the ceramic back and use them ans PINS .. Everybody like them !

Cheers

 

[M!k]

How about doing some nice pictures from them?
You'll find an inspiration here:
http://smithsonianchips.si.edu/chipfun/graff.htm


Mik

 

[greek]

Some retro design maybe? Leave the heavy math for the GHz families.

 

[hill]

No offense. I would think of establish a museum as a place for it.

 

[picotube]

I have m/b + EDO-RAM + Pentium166MHz
Can I install RTOS into the system?

 

[hill]

Surely you could, if you could find one suitable...

 

[btbass]

I have an old 386 mother board that I paid £800 for way back then. (had 4 megs of ram!) I am going to frame it, stick it on the wall in the darkened hallway, and appreciate it as a work of art.

 

[Sputnik]

One of the technology/technical drawing teachers of my school were throwing out old 486 computers (this is where I got the old processors). Now, I'm not that kind of person who allows things to go to waste (seen as I'm interested in computers). So I grabbed two computer frames (along with motherboard and power supply) in each hand and hauled these things down three stories to my mothers poor old car and shoved them in the boot (it's called a trunk for you Americans). I proceeded to fetch more, 10 in total and had to put three on the back seat. The next day, the other components such as IDE controller interfaces and others hadn't been thrown out yet, so I stuffed as many as I could into my bag and an entire box full of these cards. I dumped the whole lot into my shed (where I work on my projects) and began plugging things in, testing and tinkering. I managed to acquire a 2GB HDD from a friend for a low low price and (AMAZINGLY) installed Win98SE, what a miracle, had to overclock quite a bit to achieve this! About 4 or 5 systems actually work. The best system is a 486DX 80MHz (overclocked from 66MHz) 4 Mb RAM! Alot of work for old, outdated computer systems. But it was a lot of fun, besides the constant, mocking remarks of bystanding spectators, "Where you stealin' that from?, I'm gonna report you to the principal!". Yeah right, you do that I'm so petrified, LOSER!

I also took a monitor, but the image looks yellow is really blurring, by jiggling the VGA cable at the back it goes lighter and darker in yellow. Anyone understand this, it has something to do with the blue signal somewhere along the line.

Sputnik :idea:

 

[eltonjohn]

IS very funny you GUYS sound like archaeologists that have discovered an old civilization and make assumtions on how they used to use these machines .Well these machines were my machines not long ago .I kept a 486 for 7 years as my main computer It was a EISA base machine i HAD like 4 partions running LINUX,WINDOWS,UNIX,BSD etc .. Is not that these machines are WORTHLESS . Is that compared with the COMPLEXITY of programs this days .Is better to FORGET about .I recall being a happy man with 8 MEGs of ram .. NOW a graphic board has 128 MEGAS .. I still have 4 to 5 old SUN workstations with 16Megs and a 40Mhz Sparc .. I refuse to throw them away .. they are so well built .. But i won't use them My laptop is 2.8 Ghz and the SOFT that now i'm required to run won't run in those little boxes .. I could use them for some low level services . Like printing servers .. BUT printers are $25 why do i want a server??
So they are capable of some use . but i don't know what .. I could mention that after the first world war there were plenty of surplus planes and people would buy them JUST TO CRASH THEM ... well is the same !

 

[hill]

Hi eltonjohn,

Yes I agree with what you said. However your case is totally different from what the OP... You have the machine with old chip; the OP want to create something with an old chip...

 

[jhallows]

Despite what you guy's think the 486 is still being sold by Intel. In fact take a look at digikey catalog if you want to order one. It may not be powerful for a desktop machine but it makes a perfect embedded processor for a SOHO router, print server, or access point.

Take a look at papyaki links for datasheets.

For a BIOS: h**p://www.pcengines.ch/tinybios.htm
For a locator: h**p://www.xellsoft.com/TurboLocator.html
For a OS: UC/OS-II, Datalight ROM-DOS, or even FreeDOS

If you just want to fiddle around with processor, maybe use some glue logic, and wire-wrap a prototype take a look at this link:

h**p://www.cate.fiu.edu/Courses/EEL-4746/micros_lab/

Want to build your own North Bridge Chipset look at these links:

h**p://www.quicklogic.com/images/appnote07.pdf
h**p://www.quicklogic.com/images/appnote06.pdf

I really don't know how far you want to go but these are some pointers. There is still some back dated messages in the forum. Do a search to get some more links.

 

[Sputnik]

Here is a line up of my CPUs:

Top row: 486DX2/SX2/SX
Bottom row: Pentium 1

Sputnik :idea:

 

[hill]

Hi Sputnik,
If you really need to go for those chips, maybe single board computer... Now I'm doing the same project, but my chip is Microchip PIC18F8720...

I think I read some acticles some time ago. Intel still producing 486 chips and I read also there are many single board PC on the market. Maybe you could try to design one. Please let me know what you think on this.

 

[rauol]

THE STORY OF MY 386 machine.

I purchased my first PC a 386 with 40 MB of Harddisk (not 40 GB) and 1 MB of RAM
+ a CGA mono monitor,

i was happily typing my letters in the good old "word star 4" with my samsung 9pin
printer.

4 years back the CGA card canked off and i was not able to find one, and my good old machine was lying in my store room for the past 4 years until recently a few months back i decided to to use it for a very usefull purpose..........

I made a sculpture out of it bu pouring LOTS OF CEMENT and painted it in all colours
and you all got to beleave me it looks really good :sm21: :sm28: :sm27: :sm33: :sm30:

 

[Sputnik]

Hey there hill,

What do you mean by "single board computer"? I would be keen to learn more and experiment, if only I knew what it is.

Give us some pictures, rauol!

Sputnik :idea:

 

[hill]

Hi Sputnik,

When you design a system that needs controlling and processing power, normally you could achieve that in 2 ways.

1) An embedded solution: This normally uses a micro-controller/micro-processor as the heart of the design. The downside of this is that the firmware is hard to implement, as least if compare to second solution. Furthermore, you're in most of the time, unable to make use of your previous design for a new project.
2) Use a PC. I mean here is IBM compatible PC, or any PC that you may know. It seems like this will be a powerful machine to perform any operation that may require extensive processing power. But what if you want to build a robot, for example. You will then find that it's impractical to put a big CPU box in your small robot.

A single board computer is in the middle of above solutions. It has the benefit of embedded solution where you could easily integrate your computer in your design.

Normally it's made of a single PCB (very small if compare to PC mother board), which carries all the chips + components of your design. I give some of my opinions here: A compact flash as the HD of the system. An onboard I/O module, which could enable it controls outside world. Some basic interfaces/protocols like RS-232. And of course some RAM. To name that a lot you could add to your design.

Try also Google search with "single+board+computer". You may find that there are a lot of free resources there. For example FreeDOS, FreeRTOS etc.

Good luck.

 

[bsiswoyo]

Use Visual Basic under DOS.
You can interface it to another equipment out side PC
thx

 

[djalli]

No offense. I would think of establish a museum as a place for it.

You are right. After 100 years they maybe started as collectables.