I've gone from knowing nothing about schematics to understanding what chips are doing in 40 mins, wow you make it so easy to learn this stuff. Adam I wish my teachers in school were this good at getting the message across, if you aren't doing it already, know that you have a natural ability for lecturing. Excellent, looking forward to more of these videos. A+
Yes, he is doing a great job. I catch on to what he says almost instantly, and I'm taking a digital electronics class right now and going for a two year Industrial Electronics degree. I always end up going home and teaching myself what was presented in class, because I just don't get it when my instructor is lecturing. Fantastic work Adam!
This is by far the very best vid on RUclips that covers logic gates, I must have watched this at least 30 times now,its so satisfying to be taught something and have it actually sinking in, you sir would make a great teacher and I for one would turn up for every lesson, outstanding, thank you Adam
Oh my word. I wish I had found this video years ago. You have just made everything make sense inside my head. I cannot explain the epiphany moment heralded by this video. And, not only that but looking at your other videos, they cover everything I want to learn about. I am utterly stoked! And to round off, looking at the other comments, and in particular, who they are from, shows I'm in very, very safe hands. Seriously, thank you.
Because of this video i repaired a flasher circuit for a offshore nav-aid lantern. The IC cd4049 (invert an non invert hex buffer) pin 14 was high and 15 was high. 15 should have been low. Anyway i replaced the ic and the sync pulse was back...success!! Its people like you Adam that take the time to share what you know....thanks.
Wow, just saw your videos about the way a cpu works and this one. I've learned more in 1 hour than 1 year in technical school! Well that was back in 1985 and now it has my attention. I grew up with the Z80 and the 6502, still got the zx 81 and spectrum and also the micro professor (mpf-1). Keep up these nice videos!
Great video. I could follow you so much easier than my instructors in class. I'm taking Digital Electronics as a course in my two-year Industrial Electronics degree. I've got a test in the morning on basic logic gates and truth tables and such. Watching this while I study my notes. Great job!
Adam, I really appreciate this video. I've wanted to start using a logic probe but had no idea where to start. This is very helpful!!! I can't wait to see you continue with 101 and repair videos. Thanks!!!!
Wow! I ate this up! Watch, pause, take notes, play, rewind, take notes.... It's awesome to finally understand what all these hieroglyphs are. One thing I don't understand is what is the point of a straight buffer? How is it any different than a copper wire? 9:50 Also I am assuming a logic probe is hooked up to ground? (I have never used one)
Holy cow - what a great video, I learned so much in 40 mins.. you are an excellent instructor. I recently got into fiddling with Pinball machines - super helpful.
I want to say thank you. I'm manuele, from italy. I have printed the ON TTL data book and followed your video, repling your schematics on it. My repairs were almost "piggyback" with crossed fingers, and i do not want to do that again (imagin how long that took me to figure out a board problem). I'm going to buy a probe right now and start with some fully working boards to learn "safely" how those TTL works, then i'll try with my least-dead boards after memorising the gates. I was realy searching for something like this, so thank you very much to introduce me in, finally.
You really did a great job of breaking it down. Took me back to the first book that really helped me back in the 80's " Getting Started in Electronics " by Forrest M Mims. Was a great help to me. I just checked and its still around as a free PDF. Thanks for the video, brought back a lot of memories.
Great introduction. I'm going to show this to a friend who has a next to useless tutor / lecturer and is trying to get his head round this stuff. I have done my best over lengthy phone calls and he's catching on, but this should help him no end. Thanks man :)
Learned a lot within the first 4 minutes! I've followed John (John's Arcade) and that's how I found your channel. Keep up the great work...really enjoy your videos!
Hey Adam. I am keen to get into PCB repairs and this was a great help. Looking forward to anymore videos you produce on this topic. Thanks very much! Jeremy.
Thank you! This was really helpful! I was just sitting down tonight to find a basic tutorial on this exact topic and your video popped up in my subscriptions. Very well done.
Woah. Thank you for explaining this in a easy way. I will definitely watch more of your videos. I believe the board I am troubleshooting (stratovox) has some bad 4116 memory but I am glad you gave me another route to see if these other parts are working correctly.
Wow. I thought this video could not be improved until we got to the description of floating traces. Thanks for the education. Do floating traces display dimly on a scope? What else leads to dim traces on a healthy scope, please?
Words can not express how much this video will save my butt....actually no. Words do express it -- this video is going to save my butt! Seriously, Thank You!
Adam, this was a great primer, filled in some gaps in my growing knowledge. Could you modify the video description to include the 74 numbers covered, a couple you mentioned, a couple you didn't. Really looking forward to CPU logic, this is where I chase myself as it can be hard to interpret whats going on when a game is resetting all the time as everything happens so fast. Awesome!
High Adam, still very keen on a explanation video on arcade video. In the mean time can you suggest any resources that may help me understand old arcade video. I enjoy repairing old arcade boards like galaga, frogger, gyruss etc and your videos have help. However, the way the video sections work remains a mystery
Great video Adam! I watched the whole thing as well as your other videos, in the past. You have helped me, as well as John, to fix my Asteroids Cocktail. I was thinking of getting a Logic Probe, but I don't know how to use it. This video has changed my mind now. I have a quick question, How is your monitor hooked to your harness? What kind of monitor is it? Can you show us the rear of it? These questions are regarding your debug videos, using your nice Fluke machine. I see you and John are friends, I had asked for someone to songify your video 'blkdog7 vs brown paint' but I did it. I have the mp3, and I would like to add it to your video somehow. Thanks again! I hope you release more exciting videos soon!
EXCELLENT!!...Thank you!....I have a question: What does it mean when a pin is lasted as "Enable"?.....And as far as the vid, it's just what i needed to see...i am patiently awaiting the next vid on this. I am trying to figure out the issues with my Stargate and this vid will maybe point me in the right direction. I am trying to figure out what a 74LS139 is supposed to do at pin 15,,,and I have the TTL book you have....this helps me understand it a little...because right now I get no signal on my logic probe..no hi..no low..no beeping..nothing lighting up...like its totally dead at that pin number.
An enable turns the whole logic gate on. So for example, lets say an OR had an enable. If the inputs A and B were both 1 and the enable was 0, even though the OR should send out a 1 (because we see a 1 on at least one of the inputs) the OR would actually send out a 0 because the entire gate is turned off (disabled). In the case of the 74129, you have an 'active low' enable which means the enable has to be low for the chip to turn on. If the enable is 1... no matter what the inputs are to the gate.. all outputs will be turned off. But don't forget the bubbles on the outputs of the 74139.. instead of sending out 0's when the outputs are turned off they would output 1's.
Great video Adam, nice refresher for me. My conclusion is that one needs the schematics to trace the signal paths. Are they somewhat publically available? Now I will watch your CPU tutorial - until midnight ;)
Thanks a lot for your video, i'm trying to learn logic probe, i can understand globally how it works now, really helpfull. Did you have a link for the book? The in the description isnt available anymore. Regards.
Great video Adam! I look forward to the next one! I have the most trouble determining if ram is good or bad. Do you have any tips for checking data and address lines other than looking for pulsing. I have a fluke 9010 but only one pod and not much experience with it.
Basically the arcade game we have is a 1980s super new lines hi lo double up it was working sometimes now when u turn it on it makes a loud high pitched like buzzing the screen has colors but jumbled with no clear picture just multiple colors
You are very good at explaining this stuff. I've watched a few videos on the topic and yours clicked with me the most. I must say though the gate symbols bear an uncanny resemblance to penises. Couldn't resist.
Flops are edge triggered and take a snapshot of the inputs like a camera. Latches are also edge triggered but allow their outputs to match the inputs when the clock is high or low (depending on the type of latch).
You give some good tips. I think that board repairs are all "trade secrets" You can be qualified with engineering and not know how to or where to start with fixing a forigen board. 5☆
Lets say you want to tell the CPU when you're not drawing the screen so it can update some memory, but all you have a signal that says "I am drawing the screen"... If you send that signal through an inverter, it's meaning gets flipped, and now you have a signal that lets you know when you are not drawing to the screen. ;)
Good stuff Adam. I'm finally learning stuff because I'm tired of not knowing how to fix my PCBs. Any Logic probe recommendations? I'm hoping there's one that has a light. Some beep and that drives me nuts.
I've gone from knowing nothing about schematics to understanding what chips are doing in 40 mins, wow you make it so easy to learn this stuff. Adam I wish my teachers in school were this good at getting the message across, if you aren't doing it already, know that you have a natural ability for lecturing. Excellent, looking forward to more of these videos. A+
Thanks man!! ;)
I'll second what les said. :]
Yes, he is doing a great job. I catch on to what he says almost instantly, and I'm taking a digital electronics class right now and going for a two year Industrial Electronics degree. I always end up going home and teaching myself what was presented in class, because I just don't get it when my instructor is lecturing. Fantastic work Adam!
This is by far the very best vid on RUclips that covers logic gates, I must have watched this at least 30 times now,its so satisfying to be taught something and have it actually sinking in, you sir would make a great teacher and I for one would turn up for every lesson, outstanding, thank you Adam
This.
Oh my word. I wish I had found this video years ago. You have just made everything make sense inside my head. I cannot explain the epiphany moment heralded by this video.
And, not only that but looking at your other videos, they cover everything I want to learn about.
I am utterly stoked!
And to round off, looking at the other comments, and in particular, who they are from, shows I'm in very, very safe hands.
Seriously, thank you.
Because of this video i repaired a flasher circuit for a offshore nav-aid lantern. The IC cd4049 (invert an non invert hex buffer) pin 14 was high and 15 was high. 15 should have been low. Anyway i replaced the ic and the sync pulse was back...success!! Its people like you Adam that take the time to share what you know....thanks.
Wow, just saw your videos about the way a cpu works and this one. I've learned more in 1 hour than 1 year in technical school! Well that was back in 1985 and now it has my attention. I grew up with the Z80 and the 6502, still got the zx 81 and spectrum and also the micro professor (mpf-1). Keep up these nice videos!
The best thing on RUclips. Simply amazing instruction. Thank you for taking the time to share your knowledge.
Great video. I could follow you so much easier than my instructors in class. I'm taking Digital Electronics as a course in my two-year Industrial Electronics degree. I've got a test in the morning on basic logic gates and truth tables and such. Watching this while I study my notes. Great job!
Adam, I really appreciate this video. I've wanted to start using a logic probe but had no idea where to start. This is very helpful!!! I can't wait to see you continue with 101 and repair videos. Thanks!!!!
Great video...thank you Adam. I wanted to start doing this sort of thing, but had no idea how or where to start. I love the practical approach!
Wow! I ate this up! Watch, pause, take notes, play, rewind, take notes.... It's awesome to finally understand what all these hieroglyphs are. One thing I don't understand is what is the point of a straight buffer? How is it any different than a copper wire? 9:50 Also I am assuming a logic probe is hooked up to ground? (I have never used one)
The purpose of a straight buffer is to aid with what is called the "loading effect of multiple gates cascaded together" Google TTL fan out.
You're the first person I found who can explain this really clearly. Thanks!
Holy cow - what a great video, I learned so much in 40 mins.. you are an excellent instructor. I recently got into fiddling with Pinball machines - super helpful.
Adam, I didn't watch the video all the way yet but I am certain it's awesome. Guys, watch Adam's videos and learn stuff!! :)
If you had taught my high school electronics class, I would probably be 12 years further along with my electronics hobby.
I want to say thank you. I'm manuele, from italy. I have printed the ON TTL data book and followed your video, repling your schematics on it. My repairs were almost "piggyback" with crossed fingers, and i do not want to do that again (imagin how long that took me to figure out a board problem). I'm going to buy a probe right now and start with some fully working boards to learn "safely" how those TTL works, then i'll try with my least-dead boards after memorising the gates. I was realy searching for something like this, so thank you very much to introduce me in, finally.
You really did a great job of breaking it down. Took me back to the first book that really helped me back in the 80's " Getting Started in Electronics " by Forrest M Mims. Was a great help to me. I just checked and its still around as a free PDF. Thanks for the video, brought back a lot of memories.
Nicely done. I appreciate the work you put into these tutorials.
Great introduction. I'm going to show this to a friend who has a next to useless tutor / lecturer and is trying to get his head round this stuff. I have done my best over lengthy phone calls and he's catching on, but this should help him no end. Thanks man :)
I love the videos.. You should get a camera that focuses.. Those flip cameras are great, but they can't zoom in to see detail..
Good, basic and logical (no pun intended) information. I wish more videos were like this! When you understand this, you will have a good start.
Most useful video I've watched on the subject. Not too tech for beginners. Thank you again!👍
"I don't know why they decided to draw it this way but they did". haha. Excellent video man! Thanks!
Learned a lot within the first 4 minutes!
I've followed John (John's Arcade)
and that's how I found your channel.
Keep up the great work...really enjoy your videos!
Hey Adam. I am keen to get into PCB repairs and this was a great help. Looking forward to anymore videos you produce on this topic. Thanks very much! Jeremy.
Really love your arcade repair videos. Freshing up some stuff i learned in school, and some tricks i have forgotten about.
Thank you! This was really helpful! I was just sitting down tonight to find a basic tutorial on this exact topic and your video popped up in my subscriptions. Very well done.
Thank you for this! Now I just need to remember all this and get a data book!
Really appreciate the videos, awesome explanation!
Woah. Thank you for explaining this in a easy way. I will definitely watch more of your videos. I believe the board I am troubleshooting (stratovox) has some bad 4116 memory but I am glad you gave me another route to see if these other parts are working correctly.
I liked your explanation about logic gates , Now I understand more clearly and by doing this I can troubleshoot ICs
Thanks
Awesome! ;)
Wow. I thought this video could not be improved until we got to the description of floating traces. Thanks for the education. Do floating traces display dimly on a scope? What else leads to dim traces on a healthy scope, please?
excelente video pense que nunca iba a ocupar la logica matematica nunca la entendi pero su explicacion es de otro nivel soy de Chile muchas gracias
Absolutely awesome video chap, can only assume the rest are going to be as good.. only watched the first 20mins and learned so much already..
+Retro Video Gamer Thanks!
Thanks for posting this! I found it to be a very helpful overview, and I'll keep it bookmarked as I start into my PCB repair projects!
Fantastic video. I usually have a hard time following stuff like this but you made it easy!
Words can not express how much this video will save my butt....actually no. Words do express it -- this video is going to save my butt! Seriously, Thank You!
Cool Video and superb information :-) - Looking forward to Data Bus stuff and chip enables etc in the future.
Thanks! I'm hoping to get the next one finished up this weekend.
adam thankyou for making the video ive been doing some studying of digital circuitry and your video is very helpful to see in practice
WOW great stuff looking forward to checking some signals trying to learn some of this info Thanks
Great video Adam. Thank for making it. Sorry i am late seeing this, but it is a big help!
Thank you so much for this video! It's a great start for a novice like me :)
Thank you !
Just what I needed to start on my PCB repairs.
I appreciate the hard work. :)
Brilliant video. Love if you went through some simple debug arcade examples!
great information and very well explained!
Excellent, informative video, thanks so much!
,,,well presented man,,,you are a
good teacher
Great vídeo, very instructive. But could you please upload the TTL databook again?
Really nice intro Adam. Looking forward to more.
Adam, this was a great primer, filled in some gaps in my growing knowledge. Could you modify the video description to include the 74 numbers covered, a couple you mentioned, a couple you didn't. Really looking forward to CPU logic, this is where I chase myself as it can be hard to interpret whats going on when a game is resetting all the time as everything happens so fast. Awesome!
Done! ;)
Great, really looking forward to the next video, already the UK forum is talking about this.
High Adam, still very keen on a explanation video on arcade video. In the mean time can you suggest any resources that may help me understand old arcade video. I enjoy repairing old arcade boards like galaga, frogger, gyruss etc and your videos have help. However, the way the video sections work remains a mystery
Great video Adam! I watched the whole thing as well as your other videos, in the past. You have helped me, as well as John, to fix my Asteroids Cocktail. I was thinking of getting a Logic Probe, but I don't know how to use it. This video has changed my mind now. I have a quick question, How is your monitor hooked to your harness? What kind of monitor is it? Can you show us the rear of it? These questions are regarding your debug videos, using your nice Fluke machine. I see you and John are friends, I had asked for someone to songify your video 'blkdog7 vs brown paint' but I did it. I have the mp3, and I would like to add it to your video somehow. Thanks again! I hope you release more exciting videos soon!
Thanks Adam. Keep them coming. I love watching your repair videos.
Adam great video, keep them coming please. These are exactly the kind of videos we need to keep our games running. John go watch Adams video!
EXCELLENT!!...Thank you!....I have a question: What does it mean when a pin is lasted as "Enable"?.....And as far as the vid, it's just what i needed to see...i am patiently awaiting the next vid on this. I am trying to figure out the issues with my Stargate and this vid will maybe point me in the right direction. I am trying to figure out what a 74LS139 is supposed to do at pin 15,,,and I have the TTL book you have....this helps me understand it a little...because right now I get no signal on my logic probe..no hi..no low..no beeping..nothing lighting up...like its totally dead at that pin number.
An enable turns the whole logic gate on. So for example, lets say an OR had an enable. If the inputs A and B were both 1 and the enable was 0, even though the OR should send out a 1 (because we see a 1 on at least one of the inputs) the OR would actually send out a 0 because the entire gate is turned off (disabled).
In the case of the 74129, you have an 'active low' enable which means the enable has to be low for the chip to turn on. If the enable is 1... no matter what the inputs are to the gate.. all outputs will be turned off. But don't forget the bubbles on the outputs of the 74139.. instead of sending out 0's when the outputs are turned off they would output 1's.
Cheers, fantastic tutorial and well explained. What is the make and model of your logic probe.
Wow. I love this. What is the name of the second book you brought out? The one with the diagram of each gate. Thanks a lot.
Well, I've learned quite a few usefeul things ;) Thanks a lot ! Subbed😀
That's a great video, thanks man you explained a lot and made it clean and simple
This video helped me tons! Thanks for the great explanations.
Great video! Thanks for the thorough explanation.
Thank you very much !!! It's really great to share your knowledge, I hope I'll fix my Wonderboy in Monsterland board with your tutorial :)
Awsome video, please make more of these
Fantastic. Thank you. Very well done and I am very much looking forward to more.
Excellent, keep them coming!
Just wanted to say, great video.. thanks for taking the time to do these. Next up... CPU Logic :)
Adam, Thank you for making this Video. Learned a lot.
Very good info, thanks for sharing!
Thank you very much for the explanation also love your PCB repair video's.
Great explanations! Thanks for making this video.
Fantastic video!
Thanks for this video! It was awesome. I cannot find my probe, so I may get another one :)
Yo thank you so much for making these videos. literally so helpful!
Great video Adam, nice refresher for me. My conclusion is that one needs the schematics to trace the signal paths. Are they somewhat publically available?
Now I will watch your CPU tutorial - until midnight ;)
+Axel Haar Oh yeah you can find them all over the web. Do a quick Google and chances are you'll find exactly what you're looking for.
Thank you, this helps a lot. can't wait for more videos.
Killer video - learned a lot
Thank you so much. This was awesome!
You bet Greg! ;)
Thanks for what you are doing and God Bless
Thanks a lot for your video, i'm trying to learn logic probe, i can understand globally how it works now, really helpfull.
Did you have a link for the book? The in the description isnt available anymore. Regards.
Okay, maybe that the one : www.bitsavers.org/components/ti/_dataBooks/1981_TI_The_TTL_Data_Book_For_Design_Engineers_2ed.pdf :D
Tks for the books
Awesome Video from you adam, Glad someone did this so I didn't have to!
Great video Adam! I look forward to the next one! I have the most trouble determining if ram is good or bad. Do you have any tips for checking data and address lines other than looking for pulsing. I have a fluke 9010 but only one pod and not much experience with it.
Hi Dave, Yep my next one will be on CPU logic and it will cover those areas.
OneCircuit
Excellent ... Thanks!
Really tnx for this awsome work.
awaiting for more cool videos.
Thank you for the great tutorial. It's very much appreciated! :)
Basically the arcade game we have is a 1980s super new lines hi lo double up it was working sometimes now when u turn it on it makes a loud high pitched like buzzing the screen has colors but jumbled with no clear picture just multiple colors
My e mail is lunastarreed91313@gmail.com send me an e mail and I can send pics or video of what the machine is doing
Hey Adam, Great video!! How's the Pole Position PCB going?
very well explained,
Thanks for posting this info!
FYI the link to your TTL data book isn't active.
Love your kick ass work
Great video! Do today's modern IC's in computers work the same way?
You bet, it's just that most chips have thousands or millions of logic gates in them.. as opposed to only a handful.
Would it be fair to say all an IC really is is a combination of multiple transistors?
Yep. Transistors.. capacitors.. even resistors, all made out of silicon and other various metals/materials.
Thanks for the vid. Super informative and well done.
Do you teach this stuff professionally?
Thanks! Nah I do chip design professionally. I'd love to teach when I retire though. ;)
You are very good at explaining this stuff. I've watched a few videos on the topic and yours clicked with me the most.
I must say though the gate symbols bear an uncanny resemblance to penises.
Couldn't resist.
Thank you very much!!!!!
Thanks.. one query,. These are all edge triggered, have you ever found flat triggered ie 0-1-0. Or. 1-0-1 ? Cheers.
Flops are edge triggered and take a snapshot of the inputs like a camera. Latches are also edge triggered but allow their outputs to match the inputs when the clock is high or low (depending on the type of latch).
Thanks bro 👍 to transfering your knowledge .
Med
Thank you so much for this👍
You should really consider teaching, great video...thank you!
CyScape Thanks! Perhaps when I retire from my day job ;)
You give some good tips. I think that board repairs are all "trade secrets"
You can be qualified with engineering and not know how to or where to start with fixing a forigen board. 5☆
Thank you.
What's the point of an Inverter Gate or a NOT gate in a video game?
Lets say you want to tell the CPU when you're not drawing the screen so it can update some memory, but all you have a signal that says "I am drawing the screen"... If you send that signal through an inverter, it's meaning gets flipped, and now you have a signal that lets you know when you are not drawing to the screen. ;)
FYI, the TTL Databook link on your website is dead. :-)
DeLuSioNaL's Arcade Yeah i changed the site. Need to update that link.
Good stuff Adam. I'm finally learning stuff because I'm tired of not knowing how to fix my PCBs. Any Logic probe recommendations? I'm hoping there's one that has a light. Some beep and that drives me nuts.