where can i buy components for building hardware?

declan_lgs

sup all..
i just began to learn assembly, and would like to purchase parts for building a calculator (or somthing simple)..
where can i get some cheap components (NANDS etc..) for building hardware?

regards,
declan

declan_lgs

probably should have posted in electronics forum..
feel free to move moderator

slartibardfast

prob should considering there is nothing more dangerous than a programmer with a soldering iron, lol

rob1891

you can code logic gates if you really want to, we learnt a bit of verilog which is a c-style hardware design language, very abstract ... but we also used part of the Xilinx package (free for students) which was a lot more visual, that had us drawing gates and wires, sending inputs and checking outputs etc.

Did a few logic circuits as part of a semiconductor course, would have been fun to put it all together and make an 8 bit adder but even simple stuff gets quite big in terms of the number gates used and it would have been very difficult/impossible to just solder together transistors and diodes.

Peats have a few ICs on the wesite, say a 4 input NAND or whatever, I imagine that it would be hard to combine them to do a few functions like a calculator, at least, it would be hard to learn what each one does and how to use them.

Programmable ICs (like what your Xilinx design or verilog would get written to) would be very expensive I imagine? But at least you could run the simulation and say 'look, here's an 8 bit ripple adder, look at it add!!' ... it's a whole lot of fun ... believe me ...

rob

henbane

If it's assembly you want to learn you don't need to buy hardware - program your pc. Use a simple compiler like tasm for x86 or download an emulator for motorola 68k if you want summat a little bit more RISCy.

It's easy nuff to get software packages to emulate any kind of hardware you're interested in programming which should save you the cost of hardware.

declan_lgs

thanks both of ya's..
will look for some gates in peats..
just want to make some simple hardware, like a calculator, just ass liek a new experience :cool:
yea, im gonna learn assembly, but i wanna know how to code software and hardware.
i downloaded a cool book from overnet which goes through software and hardware development quite well, so i wanna know how to make use of both these.
will check out some emulators...
thanks again, both of ya's

Raz

If you're looking for a large selection of components try www.farnell.com
Maplin on Jervis st. will probably have a lot of the components aswell. Just browse through the catalog at the counter.

declan_lgs

thanks raz, that site looks to have lots of handy stuff..
will check out maplin next time i'm in Dublin.

Karoma

http://www.maplin.co.uk/ -- the english catalog - give you an idea of stock..

cerebus

Originally posted by declan_lgs
sup all..
i just began to learn assembly, and would like to purchase parts for building a calculator (or somthing simple)..
where can i get some cheap components (NANDS etc..) for building hardware?

regards,
declan

As some of the other posters have pointed out, you'll have to stick a *lot* of basic components together to build anything worthwhile.

Just as an example, the gate count for a really simple 4-bit multiplier I happened to have lying around is about 50 gates - a mix of low-level things like AND/NAND/OR/NOR gates and some more complex functions lke AND-ORs and OR-AND-INVERTS. Buying those components and building a circuit that doesn't do very much won't be terribly exciting. If you want to build a calculator in hardware you'll need to construct at least a MAC (multiply-accumulate) and some control circuitry - gate count blows up pretty fast.

What might be a good place to start is to look at building some of the really basic logic functions out of discrete transistors - try building an inverter, and some 2-input gates (AND, NAND, etc.) Once you've got the hang of those, try building a simple 1-bit full adder - requires a handful of basic logic gates.

If you want to earn some extra geek points and have access to some more fancy tools, try one of the free SPICE simulators (I have no idea how good it is, but 5Spice looks pretty cool). Do some transistor level simulations and check your simulation results versus your measured results from the physical circuits. (Here's where the fancier tools come in - measuring stuff like rise/fall times for transitions on the output will require some equipment)

If you have your heart set on building a calculator out of components, buy the most complex functions you can find - if you can get hold of a multiplier and an adder as discrete ICs that will make your life easier rather than having to build them from scratch.

Also, I'd suggest a breadboard for plugging things together - you should get one from the various vendors mentioned in the thread already. I think it is easier to debug any problems on a breadboard rather than soldering everything together only to find you've made a mistake and have to take it apart again.

Of course, this is all a million miles away from the way hardware is designed these days - not many people using discrete logic components anymore

As some others have mentioned though, you're probably better off building your calculator using a small uP (or an emulator) - that's (more or less) how TI/Casio/etc. do it...

One alternative, if you are in a school or third-level college, is to use something like the Xilinx toolset. As rob1891 said, Xilinx are pretty good about giving out their design software for free. I believe they supply an FPGA board pretty cheaply to educational institutions as well. This would be a great way to see how hardware works - much more up to date, using either schematic entry (draw your circuit) or synthesis from a hardware description language. The programmable device (FPGA) then gets configured in such a way as to implement your circuit and you can check the operation - the boards usually have things like LEDs and DIP switches for I/O.

Any questions, just ask. I'm sure someone on here will be able to answer anything you might come up with (though the mod may want to move this to the Electronics forum)

p

Might be worth considering getting a microcontroller:

Somehting like this:
http://www.parallax.com/detail.asp?product_id=27207
or this: http://www.trcontrolsolutions.com/basicx_files/basicx_24.htm#two

Basically they're little computers that you can hook up sensors, lights, motors and things to, in order make basic things. I'm using one right now, to create a physical interface to a computer game.

Not sure if the above ones are programmed in assembly, but there are ones out there that do, and it'd be easy for you to get to grips with, for not too much cash.

LEDs, resistors etc... can all be bought in Maplins and places like that, once you've made the initial purchase.

declan_lgs

thanks to all of ya's..
ill get BASIC Stamp 2 Educational Starter Kit to help me..
was thinking bout making a calculator from absolute scratch with NANDS, but now i think i'd be better off buying some functions and using an emulator..
thanks,
declan