Відео

@ 17:05, is the basis of faulharber (motor) wound coils?

Mine arrived with the transformer totally free and rattling around. The mounting screws had vibrated out, or were never tightened. Detecting no damage to other components or wiring, I straightened the mounting lugs, secured the transformer with better bolts and everything seems to be fine.

Very interesting! I think I'll leave building power supplies to the pros, but it's neat to see how they work.

I believe the author of that comment on Amazon simply hasn't (yet) come to understand the importance of investing in themselves (there is no better place to invest but not enough people know this as well as they should) and then sharing that investment to help others. Self-education is a daily process that should be continuous and should never end (until the end.) The price is that it takes sincere time and effort and that it also takes away that same time from people you love and care about. But it pays back to those you care about and love when you are able to help create a larger family of people who will be there when their knowledge and effort may be needed. There's some balancing to be done, different for each of us. Hopefully, the author will come to understand how important to invest time and then use their capabilities to help others. This creates a larger family -- both personal and professional -- people that it is a privilege and honor to know and who will uplift you and those around you . Everyone wins. This author needs to understand that. Also, it's simply not possible (and you address it) to write a single book that has the larger goals your book has and at the same time teach everything all the way down to binary numbers and basic logic rules. One does have to assume a certain level and target certain goals that are achievable with a book and (not to forget because I know how much effort goes into producing) 40 hours of video. You are a rare character on UA-cam. My opinion. And I value the time you've offered others here when you find the motivation and time. Thanks! I just ordered your Z80 book, today. and as a coincidence I also just received your book on core memory, today. I placed a note on video 1 of that series with a question about sourcing core. I haven't (yet) gone through your videos on the Z80 yet (less interest to me at the moment and I can only fully engage one project at a time.) But I will. I've designed and built my own computer in 1974 using TTL -- It took me a year's constant effort to learn what I needed to learn and then to implement the result (256 bytes of RAM.) That was when the MITS 8800 kit came out and a year later I was forced to debug their 4k dynamic RAM card (which didn't work, by faulty design) when I knew nothing at all about DRAM. So I learned the hard way -- 6-8 weeks of blood, sweat and tears later I figured out the 9 patch wires to bring it to life. Then I received a letter from them providing their fixes (8 wires instead of my 9.) I say all this because it will be my pleasure to read the book. (And maybe ... maybe ... spend 40 hours of time away from family to watch the videos you made -- whether or not I find that time, you have all my respect for what you are attempting to achieve in passing along your knowledge and experience here.) I will be getting out a fresh logbook and working to complete a core memory, though. That's a project that will happen. And I can't thank you enough for the care you put into the videos, which I did watch, and the book. It's your life's blood and I am its benefactor. I owe you much, already. Thanks. Oh. Final note. There is a LAW I carry in my soul -- Completion Is Everything. That rule is an iron fist to me -- don't engage a technical project you have no hope of completing and if a technical project is engaged keep going no matter the struggles along the way until it is completed (to some real sense of that word.)

Hi, Jerry. Your book just arrived, today! I do intend on getting out a fresh logbook and starting experimentation with a goal to complete a small project in the future. The first and foremost questions in my mind right now are: (1) I think you planning to provide a kit? But I believe I've not found a site, today, that has availability. That may be my failing. But I'd appreciate a suggestion from you, if possible. And (2) how might I track down a good supplier for square loop cores (of small, but varying sizes?)

I just bought a KP184 and it came with a slight dissalignment in the display . The mask in the right part of it is a little shifted I would like to know how to dissasemply it and realign Thanks any answer

There's another problem they're blowing the air over the components - in humid areas this will make the vias corrode slowly. Their manual says Humidity 5% to 80% relative humidity - no way. 45 % max if you want to have it for a few years.

Excellent video series, you are a very good teacher and instrutor

The Ethanol process was started under the second (baby) Bush administration, he received large donations from the corn farmers to require the addition of Ethanol to our fuel. They turned a waste product into something they could sell to us, and they made millions on it. So we are subsidizing the farmers by destroying our engines.

Could you please create a playlist of your logic analyzer videos? They are very informative. Thank you.

ooooooooooooooooooooooo

Did you end up releasing a book?

Hi Jerry, I have just found this because I'm about to retire and want an half decent lathe and turret mill that I can set up in my garage for jobs, i.e. e-bike kit etc. I have been in engineering all my working life (served my apprenticeship at Royal Ordnance). Current position; Technical Manager. the axis is Z not Y. (X is diameter, Z is length) you probably know this by now since the vid is 2yrs old.

Wow! I thought I was the only person that does this! I'm having the same issue now with my restoration of two Mellotron machines, or proto-sampling keyboards. I'll watch your video, but what ive been doing is putting a tire on the replacement wheel and putting the wheel in a drill that I have locked in a vice, spinning rather fast, and then I use a dremel drum sander to shape it to a perfectly round shape that is within specs. The rubber I use is from some high pressure hoses, which are high quality rubber, I'd they're not reinforced with nylon threads... and this makes them perfectly round and very "grabby", as they need to be to make the 'Tron effectively playable. After I'm done shaping them, I leave then spinning and clean them off with Naphtha and a cotton shop towel. The Naphtha cleans and conditions them, leaving them very grabby and smooth/shiny. Was curious where you source small roller bearings, as the ones I'm changing out have very small axles and the new rollers are much more open. I'll watch now, thanks. BTW, the rollers I've sourced are actually found on old 8 track tape cartridges. The rollers in those are injection molded neoprene, I believe; and are pretty nicely made. They've lasted 50 or so years with no serious breakdown. And are practically free. Going to see if I can figure something out now.

Oh the cryptic opening… z80 is dead.

Yer the dummy on ebay guy. You’re the fraud out there selling stuff that don’t work.

Maybe the book will work better than the over priced boards you sell that don’t work.

I have lost intrest to your ramblings 😮

I can see how you easly get off subject please get to the point I know you love hearing your self talking but really get to the point hey get to the point yes you have a nice British accent and you brits love hearing yourselves talking please get to the point 😮

I just purchased a mint Agilent 1670G 136 channel with opt 002, even came with ALL the pod cables, pod tips and grabbers!. I have been able to navigate the system using the manual but this series of videos was very helpful.

Now turn it into a pcb with all discrete transistors: a cpb cpu.

Only three years after you posted the video... Thank you. I found this four part series very helpful and informative. I built your fan mod from part four and it works well however there are a couple of problems with it. The zener diode on the schematic is drawn backwards while the video shows the zeners being installed the correct way around. Theree should also be a diode fitted across the fan to pretect the transistor from back emf. As the damage by back emf.

Very nice!

Microprocessor ❌ Megaprocessor✅

thank you for these vids. I don't have mine yet and maybe this is more obvious once the unit is here, but I'd like to understand where you connected that mod (other than the fan connection).

It is good to write a book, the information in a book stay much longer preserved, information in digital form flows away in the spring when attics are cleaned and old computer will meet their creator. Books on paper have the future, books in PDF have a limited use and a best-before date.

Can you use this to test a board that delivers a square wave of about 8kHz if you rectify it before putting it into the load? What about a PWM voltage that goes between 0 and 100% duty cycle?

Every time I watch a video like this I worry that it will turn you off of creating videos or writing more books... Rest assured that there are those out there who appreciate and understand what you're doing. It is so hard these days to find information on how stuff fundamentally works in discreet terms... I've built a number of z80 computers over the years, but I've always wanted to build one with completely discreet logic. Everyone says 'just use this modern chip'... that's not the point... I am fascinated by how things were done before my time and when I build a project for fun I always pick a year (i..e 1975) and make it a hard and firm requirement for the project that I cannot use any component which wasn't widely available in that year.... I've gained a lot of understanding of some thing that I've never touched from your videos and books - specifically in this case on DRAM. Though for my next project I intend to implement a much more complex bank-switching mechanism than you are using. I'll be creating a very basic mmu to map address ranges (2k pages) in the 64k CPU's range to a 22bit physical address bus. Right now I am looking forward to seeing more of your switching power supply project. I've always found power supplies to be a bit of a black box so it's great to open it up. I've actually just (yesterday) finished winding my first line power transformer using E-I steel core laminations that I found on AliExpress. This will be to power my Mark-8 computer. For this project I'm planning to design a hybrid switching supply like we've seen in some of the minicomputers you've repaired. It will be a regular 50hz stepdown transformer, and a number of switching buck regulators for the rails. It's been impossible to find information on discreet buck converters though.. Since the Mark-8 was released in 1974, my target 'date' for this is 1975. I'm using only components that were available in 1975 so the regulators will be based around something like LM741 op-amps and 2n3055 transistors. Keep up the good work! always looking forward to new videos. Hope to see some more mini-computer or discreet computer repairs coming up and of course your discreet design projects!

Speaking of the book - is it available currently? I ordered it from Amazon 6 months ago and it's yet to ship...

I recently obtained a copy of your book and am in the process of reading and studying it. I am doing my best to learn and understand the immense amount of information contained within it's pages. I just want to say thank you for making this type of information on this subject easier to discover. Right at this time I am working on trying to understand the monitor source code. I have no background or training in programming so I am doing my best to make sense of it all, but I'm sure I'll get it all figured out. Thank you again for your wonderful book.

The review gives the impression that the person just wanted a kit or step-by-step instructions on building a JMZ machine rather than necessarily understanding how you might go about designing one from scratch. I myself have been on the software side of computing for 35+ years professionally and find it rather interesting to see how such hardware designs come together and the constraints you have to work with. Who knows, maybe some day I’ll be designing putting a small system together myself rather than, say, just building a modern day equivalent to my 1st computer - a SoC MK14 kit. Love watching your videos be they tackling repairs of ancient machines or something new like the JMZ machine.

I wonder how many people bought Knuth's books and had that kind of reaction. Or, my personal favourite, Gödel, Escher, Bach. Some books are written to entertain you, these books are written to educate you. Or at least to make you think. Apart from that I have this project in my electronics drawer that may or may not some day become a full 65816-based microcomputer. I'm don't consider myself mad enough to implement dynamic RAM, although it would be much easier, but my goal is to run UNIX v6 on it ("if a PDP/11 could do it, a 65816 will certainly capable enough to do it as well" - famous last words).

it looks to me they wanted an instruction manual like you'd get from a lego set, or a piece of ikea furniture, and what they got was a massive info dump on how it all worked instead.

I’m not interested in the book or even the full schematics, but heck! I enjoyed the hell out of the videos because I grew up with Z80’s professionally. Designed a few I/O systems based on them……..but sad to hear recently that support has ended for them.

I have watched your videos and enjoyed them but I would not buy the book because I don't want to design a Z80 based system due in part to the fact I know I would need to up my skill set and I don't have the motivation at the moment. In my opinion the mystery reviewer wanted it all on a plate with no effort on his behalf (or her's) and discovered that was not what was on offer and had a hissy fit. I enjoy your work....cheers.

Dam it I now will have to buy the book. 😊

While Arduino et al have a large share in the revival of electronics as a hobby after it almost died out, I think this proliferation of all things µC through much easier access (just think of the whole burning the next eprom, try, fail, repeat cycle) has also spoiled especially young people that get into hardware coming from the software side where you just download a few snippets of code from github, tack them together, et voilà you have your new IOT thingy. There are many hardware projects around vintage chips like the z80 or 68000 that more or less consist only of the chip itself and some FPGA that contains all the rest. While the flexibility etc. of something like this is undoutedly appealing, for me its just one step away from simply using an entirely SW based solution like an emulator. I specifically like the more period correct approach of your project, it makes the process of getting it to work a truly rewarding project: you get something that could have been designed sometime in the early 80s, using the tools and parts available. If you want to build your system this way, there are a lot less projects to copy/get inspiration from today, and starting from 0 takes a lot of hours, as your videos show. Having your book as a source of "known working" circuits, specifically the CRT video output, to help with my own project (a z80 combined with a 68000 in one machine) was why I purchased it.

I think we're two of a kind, though I'm not sure of your age, you might be 5-10 years older than me but that's nothing for us oldies. :). While I would have liked to express myself in basically exactly the same way as you in the same situation, I probably would have toned it down a bit, or maybe just replied to the review with "Sorry you didn't get what you wanted". I do respect you and your knowledge and would probably enjoy your company (I don't like hanging out with people in general), but I do see why you have a "bit of a reputation" in the community that sometime surfaces when your name is mentioned in one of your subjects. Anyways - thank you for all your hard work and sharing of knowledge - keep it up end never mind all the selfish tossers out there.

I haven't built any peripherals for Z80 systems in ages, but now that I'm retired I want to get back into the hobby. Regardless of which CPU I end up using, the design process itself is basically the same. Your book is going on my next Amazon order.

I red the book twice and I never found it misaligned from your videos where you’ve pointed out repeatedly the spirit of the entire project, once got it, it’s clear that your book match it. You are the only person that I’m aware which nowadays have tried to transfer that kind of knowledge in this way. Thanks for that, It’s really appreciated, for sure from me.

Thank you very much for also showing this side of being a UA-camr/author! Everybody is entitled to their opinion and from my point of view yours was fair and also entertaining.

Jerry! I think you just forgot to include the completed computer in the package with the book! Easy fix! 😂 I admire your patience and your ability to not go completely off the rails being confronted with this amount of hybris and incompetence! The only thing I have to complain about the book is that due to my eyesight is getting worse and worse, I can't read books without glasses anymore in bed! 😬 So I blame it on you, ok? 😉

Hi, is it possible to upgrade its LCD to a bigger one, technically?

You are so right. It's been happening for a long time but coalesced during covid when people just stopped giving a shit.

Yeah, the temptation to single step is there but can one be sure that it is able to work with static clocks or would some of the setup times be reliant of very fast (8MHz) rise and fall times that would have to be conserved with the slow clock switching. What a retro microcode processor to implement a totally flexible architecture (that reminds me of mainframe platforms from that era) that was already becoming obsolete as full microprocessors were becoming common. Perhaps this was simply to implement the functions that we would soon find embedded in Western Digital disk controller ICs that would hide all this state machine workings inside a black box. I will confess that being involved in the development of disk controller hardware in those days would not have appealed to me from a stressful living aspect.

On the other side of the spectrum... I ordered a few 1 meter long shrink tubes (2mm, 5mm etc) for my lab. They arrived packed inside a 1 meter long cardboard box marked "Fragile"...

I completly agree with you and sadly it's not only on ebay. Please keep up the good and super interesting work.

I agree that the population is dumber as a result of social media but I don't think that's the root cause of the ebay issue.. I think the issue with ebay is that a lot of sellers aren't selling stuff they have any idea about and are instead parting out stuff they picked up on the cheap. They don't know what the thing really is so the symbolic bubble wrap is packing it properly to them as that's what they've been doing for all of the other random junk they found at the car boot sale and are flipping.

I have a vague recollection that we had a specification for the plug in module interfacing. NCR had a part number for the die cast covers for the plug in modules and a prototype PCB possibly so you could develop your own add on cards. The MS/DOS version that we had included a second motherboard or plug in card that had the 8086. The system was different enough that it would not boot IBM DOS but many MS-DOS programs would run fine if they did not use the special video modes.

Well, i think many people have simply lost their common sense or the ability to imagine something. Most parcel service drivers are extremly underpayed and therefor do not care anymore about the items they are handeling. Even with relatively good packaging i received parcels where the content got damaged because the parcel was obviously thrown on a hard ground or something. One have to take this into account when doing the packaging. The only (hard) way is to reclaim your money and make stress for the seller - for example leaving a bad review. I know: it does not always work. But at least there is some hope, that the seller will begin to pack better. And on eBay in particular i always contact the seller BEFORE paying to request good packaging especially for retro stuff - sometimes even offering some bonus money for that.