I've a old pc can i make a arduino of it?
There are microproccesors on the motherboard an gpu.
No, the Arduino sketches are only for some specific microcontrollers, like the ATmega328P made by Atmel.
There are microproccesors on the motherboard
.... true, but they're almost certainly going to be Intel '86 and their derivatives over the decades, not Atmel AVR processors.
Thanx for the reply's
How old is this old PC? The guys above me are right - you can't make an "Arduino" out of one, but if it's of a certain age (we're talking early/mid 80s and green/black screens here!), you may still be able to salvage some useful bits out of it.
On VERY old kit, you sometimes see MCS-48/51 family microcontrollers used for keyboard scanning processors and other low-level pin twiddling tasks. These may be useful, but are also a pain in the arse to harvest and do something with. If they're not socketed it can be quite hard to de-solder a 40 pin DIP and extract it without damage.
Also, they are probably mask-programmed with no provision for you to burn code directly on to them, and far less than 1kB of SRAM. So, you would need to set them up to execute instructions from external memory, and provide this memory for them. An EEPROM to hold your program code, and some SRAM, and more than likely some I/O expansion chips depending on what you want to do. Then the address decoding logic... and either learning some assembly language for them or finding a suitable C compiler. It's certainly do-able, you'd end up with something a little bit like this (http://www.8052.com/sbc/).
But, in the time it took you to do all that, you could have gone to work and earned enough to buy several nice genuine Arduino boards :) Your call.
You can build an Arduino in the housing of your Old PC recreating some fancy showcase!
Go ahead and make fun, but this thing runs rings around the TRS-80 I learned on. I built this about 10 years ago for the heck of it using parts I found at a surplus store.
If you're planning on salvaging parts from something older than about 1992 or so - make sure that:
1) The system is dead - that is, when completely assembled it doesn't turn on...
2) The system has no collectible value
These machines are old, and they ain't coming back. You would be surprised at what you can get for a good working 286 or 386 motherboard, to the right people (mostly industrial automation). Older stuff can be even more valuable. Really old stuff, depending on what it is, how many were made, etc...
In other words, do your research - don't assume that because it is old, makes it worthless. You will kick yourself if you found that an old piece of equipment you "destroyed" was actually worth thousands had you left it as-is - and waited. Heck - there are some old CPU variants out there that will set you back a lot of money on the collectible market...
It a pc from 2005 , the motherboard was broken and order a new one was to expecive so i bought a new one.
I think it isn't verry valuable.
Best thing to do is recycle it responsibly then :) But keep the power supply, they can be quite useful if it's not damaged in any way.