Build own motherboard out of a breadboard, or use prebuilt one?

[aPple nErd]

so im 15, and looking for a summer project. i want to build a computer. would it be better for me to buy a breadboard, and solder wires, and cpu, misc. chips on, or should i just collect some random parts of modern dat pc's, and build from there? i'm doing this to get experience, and since college is just a couple years away, and i want to be either a computer hardware engineer, or a software programmer, i thought, why not start now. the only problem is, and tutorials i look up are builds based on like 4 bit, and 16 bit chips. i want to build at least a 32 bit computer that can boot up a modern os. is it going to be just to difficult to buy a bunch of parts, a breadboard, and ram, processor etc, or is it going to be better to just find pc's that are a few years old, and take parts from them? i don't have a lot of experience with this sort of thing, but i have taken apart, and re assembled a few computers, and know how almost all of the main parts work. can someone (preferably somebody who has experience in building computers) give me some advice to get started?

oh and i should mention, my mom says if i don't make something out of the computer and electronic parts in my closet and on my desk soon, she will throw them away. i already lost a hdd this way

 

[filmbuff]

I had the idea to do this once and it turned out to be way more complicated than I thought. You can't just buy a CPU, RAM and storage and solder them on a breadboard. You need all sorts of controller chips, capacitors, obscure flash chips, etc. The simple 8-bit computer I wanted to make was 50+ components.

So yes, I would buy the assembled motherboard and put everything else together yourself.

 

[mentaluproar]

Enjoy.

 

[dukebound85]

Look into the pic16f88 chips and what not from jameco I believe. You can get some free samples if you ask

These are quite capable chips to use on a breadboard and learn how to compile and interface hardware components into

 

[aalegado]

the only problem is, and tutorials i look up are builds based on like 4 bit, and 16 bit chips. i want to build at least a 32 bit computer that can boot up a modern os. is it going to be just to difficult to buy a bunch of parts, a breadboard, and ram, processor etc, or is it going to be better to just find pc's that are a few years old, and take parts from them? i don't have a lot of experience with this sort of thing, but i have taken apart, and re assembled a few computers, and know how almost all of the main parts work. can someone (preferably somebody who has experience in building computers) give me some advice to get started?

Apologies in advance if I've misunderstood your questions.

Are you trying to learn how to be a computer assembler (a "technician" role) or building computers (an "engineer" role)? That sounds like the same thing but it's not.

Assembling a PC is what computer hobbyists and gamers do when they build a custom PC rig: They're buying off-the-shelf components and assemblies designed to work together all of which, ultimately, is intended to run, typically, a flavor of Windows or of Linux ("modern OS"). Doing this you will learn a lot about how things go together but not really much about how the components actually work. You certainly don't learn anything about programming.

Building a "computer," on the other hand, involves buying discrete components (8/16-bit CPUs, PIC-based controllers, associated support components, etc), assembling them (probably on prototyping PCBs or breadboards), and programming them using an IDE (Integrated Development Environment) on a host PC. In this, case you learn a lot of basic electronics (reading schematics, circuit assembly, trouble-shooting wiring issues, etc.) and programming. Depending on what CPU/controller architecture you've chosen (e.g. traditional PIC vs. Arduino vs. BASICStamp) you will learn high- and low-level programming.

 

[TedM]

Unless you are confident in building a motherboard I'd just use a pre-built one. Building computers is sometimes a frustrating experience.

 

[ValSalva]

Even the simplest and cheapest 32-bit motherboards are immensely complex pieces of technology with multiple layers of fine tracings and dozens if not hundred of electrical components. It would be nearly impossible to build anything remotely approaching what you could buy.

Like another poster linked to here, I'd start at Newegg. Pick components, go to town, and have fun.

 

[notjustjay]

Yeah, there are two completely different concepts here.

If you want to build a modern computer that can boot and run a modern OS, forget breadboards. Buy your parts from Newegg, buy a case, slap them together, install an OS, and go.

If you want to build a computer, for the sake of understanding the basic building blocks that go into one, then you want to start with a very simple 8-bit CPU like you've mentioned you've seen in tutorials. You might look at building a simple computer from a Z80 or 6502 processor (the heart of the original Apple). You can build a simple 8-bit A/D bus, add a simple static RAM chip, simple UART, etc. using a breadboard. You'll probably want an EPROM for the basic ROM code that you'll write, and an EPROM programmer to get it in there. You'll be writing your own programs from scratch in assembly (or I'm sure there are existing ones floating around). Your basic I/O components will probably be things like discrete switches, LEDs, maybe an LCD display module. This is EXTREMELY low level stuff but it is also incredibly educational and, I find, really fun.

I imagine there are also tutorials out there to build some basic XT-class machine of your own using an 8088.

Nerd alert: I actually had a plan to do this when I was in ninth grade or so. I found a book in my school library that explained the hardware so well that I felt confident taking a blank sheet of paper, laying out a Z80 and some basic ICs, and drawing bus wiring between them. I never did get around to actually building one though.

 

[aalegado]

I imagine there are also tutorials out there to build some basic XT-class machine of your own using an 8088.

Cleaning out my parent's house for a recent move I found an old, full-size XT mobo. I remember winning it in a raffle but we already had a 386SX-based machine in the house so there wasn't a need (or the money) to populate the board!

If you want to build a computer, for the sake of understanding the basic building blocks that go into one, then you want to start with a very simple 8-bit CPU like you've mentioned you've seen in tutorials. You might look at building a simple computer from a Z80 or 6502 processor (the heart of the original Apple). You can build a simple 8-bit A/D bus, add a simple static RAM chip, simple UART, etc. using a breadboard. You'll probably want an EPROM for the basic ROM code that you'll write, and an EPROM programmer to get it in there. You'll be writing your own programs from scratch in assembly (or I'm sure there are existing ones floating around). Your basic I/O components will probably be things like discrete switches, LEDs, maybe an LCD display module. This is EXTREMELY low level stuff but it is also incredibly educational and, I find, really fun.

I had an experience doing this in high school (in the 80's). We had a class where the semester project was for each student to build the same 8085-based, single-board computer—we were given the schematic and told to go for it. We could build it anyway we wanted (breadboard, point-to-point perf board, custom PCB, wire-wrap, or a combination of methods). To test it, we each had to program an EPROM with the same machine language program. If you built the computer properly, the program would cause a square wave of particular frequency to be available on a particualr pin of the CPU.

For someone getting into electronics/computers at this level now I'd probably recommend against doing it with old school CPUs like this—there's just too much support circuitry and equipment needed besides the basic, electronics-competence you need to put something like this together.

On the other hand, if there's a Maker group in one's area one might be able to join them and use their resources.

Maker group or not, it's easy now to take something like an Arduino, PICAXE, or BasicSTAMP since they are easy to interface to simple electronic circuits (i.e. LEDs, switches, speakers, etc.) and still feature rich programmability via their respective IDEs.

Here's a link for OP:
http://en.wikipedia.org/wiki/Arduino

 

[shinji]

http://en.wikipedia.org/wiki/Raspberry_pi

But if you need a PC for Windows, just use an off the shelf motherboard.

 

[notjustjay]

Maker group or not, it's easy now to take something like an Arduino, PICAXE, or BasicSTAMP since they are easy to interface to simple electronic circuits (i.e. LEDs, switches, speakers, etc.) and still feature rich programmability via their respective IDEs.

True. Building a full computer from scratch might be better left as a thought exercise today. You're right, you could get up and running so much faster with a PIC or Arduino. I played with HC11 micocontroller boards (the "Handyboard") for my university fourth-year project. Fun stuff.