Make a computer from scratch kits?

Is there anything like this out there? I don’t mean putting together your own Windows 8 system with off the shelf parts, but more like something where you build a basic computer around a 6502 or Z80 processor and various other parts on a breadboard.

I guess what I’m looking for is something where you put together a basic computer and learn how all the parts interconnect and work with each other at a very low level. I don’t have a lot of electronics experiences beyond those Radio Shack 200-in-1 type kits. I understand the basics of transistors and logic gates and I know what the various electronics components do in general. I understand the basics of how a computer works (I’m pretty familiar with 6502 op codes and its general architecture), but I don’t know how ICs interact exactly with “the rest of the world” in a real way, just an abstract one.

With that vague description, is there anything out there that might interest me, that might give me the foundation to build a basic computer “from scratch.” I’ve found some computer projects online, but I’m wondering if anyone has something more formalized that starts with the basics and ends with creating a basic functional computer.

“Microcomputer trainer” is what they called that back in the day.
You probably can find one for the CPUs you mentioned. Z-80 architecture is still current, lots of commercial applications.

Ebay has one for sale. New
http://www.ebay.com/itm/Micro-Computer-Trainer-Intel-8085-Based-With-128-page-Lesson-Manual-Brand-New-/251296925169?pt=Educational_Toys_US&hash=item3a8276c5f1

Ooo…that looks like fun. I’m not entirely sure where I’d rate my soldering skills. Good enough to mod an XBox back in the day, so I suspect I’ll be okay with that.

I remember my microprocessor class used a trainer with a Motorola based chip. We learned all the OPCodes and registers.

I was surprised to see someone selling a trainer. I’m guessing it must be New Old Stock.

That looks pretty kewl.

Yeah, back in electronics school, we got a box of parts, a book of instructions, and a wire-wrap tool. And a deadline when it had to be handed in.

We built a card-cage, shoved sockets into printed-circuit cards, soldered together the power supply, shoved chips into sockets, wire-wrapped the heck out of everything, plugged it it… and hoped it worked.

Mine worked for a long as it needed to, in order to be marked. I passed. :slight_smile:

There also this old Tandy one. It looks a lot more basic, but I’m happy to take baby steps. Has anyone fooled around with this one?

68HC11-series briefcase with the little pink tech ref book for our microcontroller classes. Later was the Alterra FPGA dev panel.

I like the looks of the Ebay one better than that Radio Shack one. The RS one looks like it has those quick connect spring contacts; no soldering necessary. If you have to solder sockets to the board and then put the ICs in the socket, it should be tedious, but a piece of cake. If you have to solder the ICs directly to the board, you’ll want to be really careful.

Yeah, that’s exactly what it is–it’s like the other Radio Shack X-in-1 kits or crystal radio kits or whatever. It’s just springs and you get a bunch of insulated wire cut to different lengths and already stripped at the ends and connect spring-to-spring. Which is cool if you want to experiment and see what happens when you connect X to Z instead of Y or whatnot (providing you don’t blow something in the process.)

computers aren’t like those learn electronics labs.

they are much denser packed and layout and position are critical.

I’m not looking to build a MacBook Pro. I just want to know how something like a Steve Jobs era Apple I or whatever computer they made in their garage was made. Or how to make something like this. It could be the hackiest ugliest looking piece of electronics on earth. I don’t care if the computer is the size of a living room, I just want to learn how all the basic parts interact on a basic level. I just basically want to know how to make a 70s era garage-built computer.

I’d strongly suggest getting a good quality variable power soldering Station with several tips. You need a really fine tip for PCB (Printed Circuit Board) work and low power. Too much heat and you’ll lift the pad right off the PCB. Switches and IC sockets need a bit more power. Having a variable unit is essential.

this Weller is a reasonably priced one with features that are needed. Weller is the brand I’ve used throughout my career.

Your standard $9 Radio Shack 40W iron is just too hot for PCB work.

Sweet! Thanks for all the advice. I actually dug out my old 200-in-1 kit, so I could start with some basic logic on that, and then I found a nice online tutorial and schematic for building a four-bit adder from transistors (basically using a chain of logic gates), so I’m thinking of starting with that and moving up to a microcomputer kit like above.

It’s fascinating for me to see how this works on a real level. I mean I know Boolean algebra and bitwise operands and things like that, but I’ve never really seen or really thought about how it works electronically (minus some long-forgotten knowledge about logical gates) when interconnected.

Layout and position only matter at super-high clock speeds.
Something running at 4 or 6MHz will work fine on a solderless breadboard. I’ve done it. :slight_smile:

I don’t think you’ll need mad soldering skillz or a super high quality soldering station with an old school PCB like that. Everything is through-hole and wide pitch. Piece of cake

Do any of these kits include any sort of output capability to a TV or monitor? That’s one thing I could never quite figure out - how you would, say, display a lower-case “a” in a particular part of the screen. (Presumably, it’s as simple as (a) having a block of memory set aside for the video (e.g. for a 640 x 480 x 16-color (the original EGA?), you have 640 x 480 / 2 bytes, with each byte being two 4-bit values representing the colors of two pixels), (b) getting the OS to place the character in the right place in the memory, and © somehow converting the screen memory to something that can be sent to the monitor - it’s © that I can’t wrap my head around.)

Student these days seem to do their logic labs using FPGAs, which aren’t nearly as much fun. When I was in school we connected up little cards with a couple of NAND gates or a flop. Actually connecting stuff is a lot more fun.

You want to acquire a copy of The Cheap Video Cookbook, by Don Lancaster.
Basically, you read in the bits, shift them out, convert to video, and Presto!

(The book is quite dated, but answers your questions in detail)