How to Build a Computer on Breadboards Using Transistors

[@simpleelectroniccircuits4268]

simplest computer on the planet.Thank you for making that.🎉🎉🎉

[@GlobalScienceNetwork]

Sure thing, that was actually the goal. Building the simplest computer that allows people to understand how it works. Thanks for realizing it!

[@rileyrussell2460]

Awesome job! Thank you for showing how the computer both adds and subtracts too!

[@GlobalScienceNetwork]

Sure thing, thanks for watching!

[@Enigma758]

This is brilliant! I can appreciate the thought and dedication that you put into designing and building this. No doubt, building a computer from the transistor level provides a very deep level of understanding. I can't wait to see more of your videos and I can't say enough good things about your channel. You are also a talented communicator!

[@GlobalScienceNetwork]

Thank you. I am glad you found it helpful! I am working on the ring counter right now so more videos to come soon!

[@ying6726]

Your content is amazing I look forward to seeing more!

[@GlobalScienceNetwork]

Thanks! I am working on some projects now. Hopefully, I get them posted soon!

[@velmurugans90]

Nice explanation. Thanks. Please do more videos.

[@GlobalScienceNetwork]

Thank you, I do plan to make more videos!

[@sharadkumarsingh4802]

Refreshing to see this after years when Ben Eater built his 8 bit one 😉

[@GlobalScienceNetwork]

Ben Eater does a good job explaining things from what I have watched. This computer is different as it uses individual transistors rather than ICs. I think this leads to a further understanding of how a computer works. Having a solid understanding of the fundamentals will be important when we build more advanced computation methods in future videos. Which should be awesome! Thanks for watching!

[@sharadkumarsingh4802]

@@GlobalScienceNetwork yes I understand the huge difference b/w yours and his computer and I greatly appreciate your effort 😉

[@SunLake-pr1di]

Ben eater should be proud

[@GlobalScienceNetwork]

Yeah, he would probably find the transistor level build interesting.

[@daniellane9732]

Awesome project. Can't wait to see how the tri state buffers are built.

[@GlobalScienceNetwork]

Yeah, it is interesting how they work. I show the circuit diagrams in this video and in the completed 4-bit computer build. In the future I plan to make a separate video about how tri-state buffers work. Let me know if you have questions.

[@daniellane9732]

That's the only thing that is hanging me up. Do you have a schematic for them?

[@GRSG_tech]

thank you, make more video's like this :). GREAT JOB !!

[@GlobalScienceNetwork]

Thank you, I do plan to make more videos!

[@riemanneconomy7688]

Wish you could do a detailed video of how to wire all pf this. This is beyond great 👏 congrats

[@GlobalScienceNetwork]

Yeah, I will be making more videos explaining each part in detail. If you watch the digital logic gate video and data flip videos you will have a good idea of how to build each section. Once you understand that connecting each section is not difficult.

[@aligunaydn9912]

thank you

[@GlobalScienceNetwork]

Sure thing, I was going to wait until it was 100 percent complete to post the video. But realized at this point it is actually easier to show how it works. I plan to have it 100 percent done soon. Thanks for watching!

[@aligunaydn9912]

What resistor value do you use most?

[@GlobalScienceNetwork]

Most of the resistors are 2.2K. You can use 1K-2.2K but 2.2k will use less power. The main resistors that are different are the 100K resistors used on the input buffers and then different resistors for the clock which are 1k, 10K, and 100K.

[@aligunaydn9912]

@@GlobalScienceNetwork thanks

[@nasiruddinmahmud3330]

i appreciate what you do. can i know which transistor you used? all of them are the same transistors or different mixed? can i use any NPN transistor here?

[@GlobalScienceNetwork]

I used 2N2222 or 2N3904 NPN transistors. All the transistors can be either type. Other transistors with similar properties will also work. You can try and build simple logic gates with them to test if the transistor will work. Some NPN transistors will not work as logic gates.

[@muhammadakoodi]

Hi. I am attempting a similar project, but I encounter the problem of a loss of signal voltage after passing through all of the logic gates. Also a tri state buffer video would be appreciated. Keep up the great work. Thanks

[@GlobalScienceNetwork]

These projects are a good learning experience. If the proper logic gate configuration is used each logic gate should be able to send a signal to the next gate without losing power. Some of the basic logic gates shown on websites or even textbooks only work as stand-alone logic gates. If you watch my logic gate video I explain this in more detail. If the data flip flops or circuit was working before hooking them up to a larger circuit then capacitors on the power rails can help with small voltage variations. I will be making a video about the tri-state buffers in the future as well. My goal for the videos is to explain things so people can build the entire computer so let me know if things are unclear.

[@hainshj]

Muito legal, parabéns! Sempre pensei em fazer algo parecido, mas ainda não tive tempo para isso.

[@GlobalScienceNetwork]

Obrigado! Você pode começar a criá-lo uma seção de cada vez. Demora um pouco. Confira meu vídeo mais recente onde terminei de construir o computador de 4 bits.

[@plantor0728]

How would I go about making this smaller version of the 4 bit computer? I found the logic gate schematic for the larger one on your website but I couldn’t for this smaller one

[@GlobalScienceNetwork]

Good question. This is just the first half of the larger computer. Basically it is the right half. You can test the computer when it is half built. So the diagram would be the right half of the larger version.

[@plantor0728]

@@GlobalScienceNetworkwait wouldn’t I need the other half for this project, to get like the ring counter and stuff or is it just extra things that aren’t needed

[@GlobalScienceNetwork]

@plantor0728 Well they are needed for a full computer but in this video, I show how you can test the first half of the computer. Each section can be built and tested separately and then combined to make the full computer.

[@plantor0728]

@@GlobalScienceNetwork oh then that’s perfect then, thank you for the help

[@SyldabiaHacks]

I think you could put it all into an integrated circuit, and invent the microprocessor. You'd be a millionaire.

[@GlobalScienceNetwork]

Ha ha that is a great idea!

[@pixelgoose98]

it would be cool to see more features like more opcodes eg. ldi and a buncha others, memory and memory access, and a seven segment display

[@GlobalScienceNetwork]

I have another video with a similar title where I show the completed computer with the opcodes, decoders, counters, control-matrix etc. A seven-segment display would be cool as well. Since the numbers are low it is pretty easy to know the numbers in binary.

[@pixelgoose98]

@@GlobalScienceNetwork thats cool, btw, i tried making a nand gate full adder from transistors, but the carry out is constantly on for some reason, idk if it is loose connections in my breadboard, what do i do?

[@GlobalScienceNetwork]

@@pixelgoose98 It could be a bad transistor. Try swapping them all out. If that does not work then check to make sure it is wired properly really closely. You can check the logic of each NAND gate to see which one is not working.

[@pixelgoose98]

@@GlobalScienceNetwork jut checked it and its working! turns out it was like a 100 loose conections, will u guys ever make transistor computer tutorial?

[@GlobalScienceNetwork]

@@pixelgoose98 Nice, yeah troubleshooting can be tricky. Well, this was part one, and the transistor computer was finished in the next video. It seems you are on the right track with figuring out how to build it, start with logic gates, then flip flops and adders, and then work on building the registers and counters. If you work your way up from the basic videos my goal was for this video series to show enough detail to be a full tutorial. I even show the logic gate diagram of the entire computer.

[@ClashingJunction]

Other youtube channels:- we will start with our first program "hello world" Global science n/w :- lets first build our own computer before that 😂

[@GlobalScienceNetwork]

Ha ha when I took my first programming class in HS I was surprised. I thought this was not actual programming, this is typing in a program someone else programmed. I mean let's at least start with machine code.

[@mtg-7452]

what are the name of these transistors

[@GlobalScienceNetwork]

The transistors are 2N2222 NPN BJT transistors. You can also use model 2N3904. If you watch the logic gate video I start by describing how these work.

[@treadmillrepair754]

Amazing.

[@GlobalScienceNetwork]

Thank you!

[@SukiYaki1904]

how much volt is your power supply?

[@GlobalScienceNetwork]

I powered the computer with a 5V 2 amp battery pack.

[@SukiYaki1904]

@@GlobalScienceNetwork Okay, tysm, i'm going to try to make something similar with breadboards

[@GlobalScienceNetwork]

@@SukiYaki1904 Sweet! Good luck! Let me know if you have any more questions.

[@SukiYaki1904]

@@GlobalScienceNetwork Yeah, I have one, how much 4 bit registers can fit on 1 breadboard, jk flip flop or data flip flop.

[@nomann5244]

but where is the circuit diagram? is there any link for the circuit diagram

[@GlobalScienceNetwork]

In my latest video, how to build a 4-bit computer, I finished building the computer and provide a full logic gate level circuit diagram for the computer. The video is in 4K so it should be about as clear as the original. If you would like the diagram as an image, email me and I can send it to you.

[@nomann5244]

Thanks for your circuit diagram❤️ I have got it!

[@gabe-g4j]

il clock è stabile? con il multi vibrator?

[@GlobalScienceNetwork]

The astable multi-vibrator is just one simple way to make a square clock waveform. Even if you used a 555 timer it would be operating in astable mode.

[@gabe-g4j]

@@GlobalScienceNetwork understood, nice project anyway, bravo

[@GlobalScienceNetwork]

@@gabe-g4j Thanks!

[@GlobalScienceNetwork]

@@gabe-g4j Also, I have the full computer built now and will be posting the next video soon!

[@gabe-g4j]

@@GlobalScienceNetwork great, interesting! :)

[@grassSherman]

But can it run doom?

[@GlobalScienceNetwork]

Ha ha that would be good goal!

[@ShannonJosephGlomb]

I believe it will ❤❤❤❤❤❤❤ once we start putting them on silicone and pcbs with smds it would look amazing on a pcb with tiny smds and then put them on the wall yeah especially having gpu going to led dot matrix 😊

[@ShannonJosephGlomb]

I would build this in a heartbeat if I had cash to order all the components right now ❤❤❤❤❤❤❤ then make it my wall hanging decoration as I make them especially the artificial neurons all massive would be amazing 😊

[@GlobalScienceNetwork]

Yeah, that would be cool. I do have the 4-bit computer in a picture frame right now!

[@youtuuba]

Interesting video, but there are some glaring problems: - Incorrect terminology, in the sense that the word "byte" is being used to refer to a 4 bit word; the correct name for this is "nibble" (or half of a byte). - While this structure is part of a computer, it is not in its entirety a "computer" according to the conventional definition. It is apparently not able to execute a stored program, as evidenced by all the manipulations shown in the demonstration. It seems to only store data in its tiny memory, but the 'program' appears to be only in the mind of the operator, hence the manipulations (and it seems to not have the capacity for decoding stored instructions, if there were any). So, nice work on the building blocks, such as they are. But potentially very confusing to viewers who are just learning and don't know any better when the video presents one thing as another and uses misleading terminology.

[@GlobalScienceNetwork]

Thanks for the feedback. This is a sort of a part one and I explain at the end that I will be building the rest. I thought it would be helpful to show the manipulations by hand before showing the entire computer using the control matrix as this might be information overload. I have the computer finished now and am making the video for it now so the video should be posted soon. I am doing this to teach others and learn so I welcome constructive feedback. If it was an 8-bit computer I think your terminology is correct when the byte is split into two 4-bit parts. Since this is only a 4-bit machine I think referring to it as a byte is correct.

[@youtuuba]

@GlobalScienceNetwork , all the referenced I have define a "byte" as being 8 bits wide. I am pleased to learn that you have enhanced your device, and look forward to seeing the new video.

[@desertfish74]

@@youtuubathere’s a difference between a byte, and an octet. The latter being the unambiguous name for a collection of 8 bits.

[@youtuuba]

@desertfish74 , well, all I can say is that I am one of the people who was there in the early days of microprocessors and personal computers, and recently completed a career in computers, and so far I have never encountered the use of the word "byte" to mean anything other than an 8 bit word, and "nibble" was always used to refer to a 4 bit word. I guess there may be some 'camps' that use different terminology, but since this video purports to be educational and targeted at newbies, use of the word "byte" over and over when referring to 4 bit words it more likely to cause confusion. I just did a bit of Googling, and found many definitions that say "byte" and "octet" are synonymous, and many websites that say that a "nibble" is four bits and is often used for half of a "byte". I do see some places that say while the word "byte" is not universally identified as 8 bits, nonetheless it is the generally accepted standard definition, and that when " byte" is on occasion used for anything other than 8 bits, then "octet" should be used to unambiguously mean 8 bits, but in those instances the author of the document should make it clear up front how they are defining their terminology. I doubt that newbies are likely to benefit from the word "byte" as it was used in this video.

[@GlobalScienceNetwork]

@@youtuuba Thanks for the feedback. I will plan to point this out when making the memory module video. For the next video, which I already made, I might just put a note on the drawing. I do see that many people refer to a definition of a byte as you describe. I like calling 4-bits a byte for this 4-bit computer as it can be fetched by memory and it is the full number being used. In some cases, this is how it is defined. To be honest I thought a byte could be 4, 8, 16, 32, or 64 bits. Since you are correct this is for educational purposes I do want to explain the terminology used.

[@arcadebuilder533]

Schematic??? Please!!!!!😳

[@GlobalScienceNetwork]

I will be posting another video soon that shows the entire computer. I show logic gate-level drawings for most of the computer and if you watch my video on digital logic gates you should be able to figure out how to build the entire computer yourself. I also have videos of the ALU, full adders, flip flops, and binary counter at the transistor level. Each circuit can be built separately and then connected together later.

[@LexLuther-sf3zm]

This is insanely tedious

[@GlobalScienceNetwork]

Are you trying to build it?

[@daniellane9732]

I am trying to build it I am stuck on the tri state buffers.