The Transistor that Changed the World -- the MOSFET

Another great video from Asianometry.  

My only quibble is that it kind of left unclear the differences between JFETs and MOSFETs.  After all, we still use both.  Note our beloved J310 JFET.  And the IRF510 is a MOSFET.  

Google's AI explains: 

A JFET (Junction Field-Effect Transistor) and a MOSFET (Metal Oxide Semiconductor Field-Effect Transistor) are both types of field-effect transistors, but the key difference is that in a JFET, the channel conductivity is controlled by a reverse-biased PN junction, while in a MOSFET, it's controlled by an electric field across an insulating layer between the gate and the channel, allowing for a much higher input impedance and greater design flexibility in MOSFETs; essentially, MOSFETs are considered a more advanced version of JFETs with superior performance in many applications like high-speed switching and integration into complex circuits. 

The Surprising Difficulty of Analog Circuit Chip Design -- AI to the Rescue?

https://www.youtube.com/watch?v=lNypq1XuZRo

Really interesting.  Why the design of the analog portions of chips is so much harder than the design of the digital portions.  

Great channel. 

A Really Cool Homebrew Computer

Wow, very cool.  On Hack-A-Day this morning:

https://hackaday.com/2024/05/26/homebrew-computer-from-the-ground-up/

It caught my eye because the architecture seems similar to that of the MostlyDIYRF PSSST rig.  

There is a lot to learn from this little machine, especially for an analog guy like me. 

Mostly DIY RF PSSST

"The Soul of a New Machine" -- Re-reading the Classic Book by Tracy Kidder

This book is especially important to the SolderSmoke community because its title has led to one of the most important concepts in our community and our lexicon:  That we put "soul" in our new machines when we build them ourselves, when we make use of parts or circuits given to us by friends, or when we make use of parts (often older parts) in new applications.  All of these things (and more) can be seen as adding "soul" to our new machines.  With this in mind I pulled my copy of Tracy Kidder's book off my shelf and gave it a second read.  Here are my notes: 

--  On reading this book a second time, I found it kind of disappointing.  This time, the protagonist Tom West does not seem like a great person nor a great leader.  He seems to sit in his office, brood a lot, and be quite rude and cold to his subordinate engineers.  Also, the book deals with a lot of the ordinary stupid minutia of organizational life: budgets, inter-office rivalry, office supplies, broken air conditioners. This all seemed interesting when I read this as a youngster.  But having had bosses like West, and having lived through the boring minutia of organizational life, on re-reading the book I didn't find it interesting or uplifting.  

-- The young engineers in the book seem to be easily manipulated by the company:  They are cajoled into "signing up" for a dubious project, and to work long (unpaid) hours on a project that the company could cancel at any moment. They weren't promised stock options or raises;  they were told that their reward might be the opportunity to do it all again. Oh joy.   This may explain why West and Data General decided to hire new engineers straight our of college: only inexperienced youngsters would be foolish enough to do this. At one point someone finds the pay stub of a technician.  The techs got paid overtime (the engineers did not), so the techs were making more money than the engineers (the company hid this fact from the engineers). The young engineer who quit probably made the right move. 

-- The engineers use the word "kludge" a lot.  Kidder picks up this term.  (I'm guessing with the computer-land pronunciation that sounds like stooge.)  They didn't want to build a kludge.  There is one quote from West's office wall that I agree with:  "Not everything worth doing is worth doing well." In other words, don't let the perfect be the enemy of the good.  Sometimes a kludge will do. 

-- Ham radio is mentioned.   One of Wests lead subordinates was a ham as a kid.  Kidder correctly connects this to the man having had a lonely childhood. Heathkit is also mentioned once, sarcastically.  

-- The goal itself seems to be unworthy of all the effort:  They are striving to build a 32 bit computer.  But 32 bit machines were already on the market.  The "New Machine" wasn't really new.  

-- Kidder does an admirable job in describing the innards of the computer, but even as early as the 1978 models,  I see these machines as being beyond human understanding.  The book notes that there is only one engineer on the hardware team who has a grasp of all of the hardware.  The software was probably even more inscrutable. 

-- I found one thing that seemed to be a foreshadowing of the uBITX.  The micro code team on this project maintained a log book of their instructions. They called it the UINSTR.  The Micro Instruction Set.  Kidder or the Microkids should have used a lower-case u.     

-- The troubleshooting stories are interesting.  But imagine the difficulties of putting the de-bugging effort in the hands of new college graduates with very little experience.  I guess you can learn logic design in school, but troubleshooting and de-bugging seem to require real-world experience.  We see this when they find a bug that turns out to be the result of a loose extender card -- a visiting VP jiggled the extender and the bug disappeared.  

-- Kidder provides some insightful comments about engineers. For example: "Engineering is not necessarily a drab, drab world, but you do often sense that engineering teams aspire to a drab uniformity."  I think we often see this in technical writing.  Kidder also talks about the engineer's view of the world:  He sees it as being very "binary," with only right or wrong answers to any technical question.  He says that engineers seem to believe that any disagreement on technical issues can be resolved by simply finding the correct answer.  Once that is found, the previously disagreeing engineers seem to think they should be able to proceed "with no enmity."  Of course, in the real world things are not quite so binary. 

-- This book won the Pulitzer prize, and there is no doubt about Kidder being a truly great writer, but in retrospect I don't think this is his best book.  This may be due to weaknesses and shortcomings of the protagonist. I think that affects the whole book.  In later books Kidder's protagonists are much better people, and the books are much better as a result: for example, Dr. Paul Farmer in Kidder's book  Mountains Beyond Mountains. 

-- Most of us read this book when we were younger.  It is worth looking at again, just to see how much your attitudes change with time. It is important to remember that Tracy Kidder wrote this book when he was young -- I wonder how he would see the Data General project now. 

-----------------------

Here is a book review from the New York Times in 1981: 

https://archive.nytimes.com/www.nytimes.com/books/99/01/03/specials/kidder-soul.html?CachedAug

Here's one about a fellow who also re-read the book and who provides a lot of good links: 

https://auxiliarymemory.com/2017/01/06/rereading-the-soul-of-a-new-machine-by-tracy-kidder/

The System Source Museum (Computers, Maryland)

Thanks to my friend Bob KD4EBM for alerting me to this.  Bob provides some very useful background: 

https://museum.syssrc.com/

(Just north of Timonium, colocated with the future home of the National Electronics Museum)

System Source has a computer museum displaying technology from the inception of computing. Founders Bob Roswell and Maury Weinstein opened ComputerLand, a predecessor to System Source, in 1981. Rapid advances in technology in the early 1980’s made some ComputerLand inventory obsolete before it could be sold. Bob and Maury’s old ComputerLand store on Redwood Street had a bank vault in the basement, so they filled it with vintage tech.

Wow, that bank vault in the basement is really intriguing.  We need to find more of those.  

The Usagi guy's 6AU6A T-shirt is pretty cool.  I also liked his reference to Tracy Kidder's book "The Soul of A New Machine."  I happen to be re-reading that book now.  I'm struck by the complexity of even the computers of the late 1970s.  At one point Kidder notes that there is only one guy on the hardware team who has a complete grasp of how the hardware in the new machine actually works.  The software was probably even more inscrutable.  And of course, things have gotten a LOT more complex.  This is the big reason that I have decided to stick with simple, analog, discrete component, HDR rigs that I can understand.  To each his own.  One look at the wiring on some of those old computers tells me that this is not for me.  

Computer Science is DOOMED Because Humans are Bad at Programming (Video)

Wow, this video of Dr. Matt Welsh's presentation to the CS-50 class at Harvard really put the whole AI, large language model into perspective. It came at a very good time for me, because for past week or two I have been struggling with what was, essentially, a programming problem.  (Dean KK4DAS got it fixed, but the fact that it wasn't easy made me think about the software problems discussed in the video.) 

So much great stuff in this video: 

-- Shel Silverstein!  Yes!  We have discussed him before. The guy who wrote both kids books and articles for Playboy magazine.   The author of "The Cover of the Rolling Stone" for Dr. Hook and the Medicine Show ("The thrill that'll hit ya...") 

-- Pong.  Toy Story (Mark K6HX worked on this).  War Games. 

-- The connections between EE and CS.  Slide rules. 

-- "ChatGPT is like an eBike for the mind."  (But it seems like the jump from Rust to AI is a lot more significant and involved than the jump from bike to eBike.) 

Matt's presentation made me feel a LOT better about never having learned a programming language. And it made me feel a lot better about never having forced my kids to "learn how to code."  I always thought that there would be PEOPLE who were better at this.  As it turns out, the AI is better at that.  

Matt's admission that we don't really know what is going on in the large language models was really interesting.  Especially his description of the "empirical discovery" of the need to use the phrase "let's think step-by-step." 

His description of the cost economics behind today's programming vs. the cost of future (AI-based) software development should be quite sobering for many.  

I found the video on this article: https://thenewstack.io/if-computer-science-is-doomed-what-comes-next/

Video on Discovery and Restoration of the Apollo Guidance Computer

I've probably posted before about CuriousMarc's efforts to restore the DSKY Apollo Guidance Computer.  But this Wall Street Journal video sums it up and adds detail about where the computer they worked on came from:  the guy in the video found it discarded in a junk warehouse that he bought in the 1970s!  Those of us who scour those under-the-table parts boxes at hamfests will appreciate this find, and the ensuing restoration. 

Apollo Core Rope Memory -- CuriousMarc Takes it on (video)

Here is another amazing Apollo video from CuriousMarc (AJ6JV).  Thanks to Bob KD4EBM for alerting me to this. We have recently been discussing the "Apollo rope memory" as I read Sunburst and Luminary by Don Eyles (ex K4ZHF). In this video Marc and his colleague Mike get ahold of some actual Apollo memory modules, develop a device that allows them to read it,  and they discover a design error.  Wow.  

My analog HDR head hurts after watching this.  Even Marc says he was approaching his limits in explaining all this.  

I had not heard of the bug they discovered in the Apollo 11 software just a month before launch, and how they had to climb into the Saturn V to fix it.  Amazing.  

Thanks Marc, thanks Mike and thanks Bob. 

Sunburst and Luminary: Apollo "Rope" Memory, and other items of interest

 

Wow.  That is the method that they stored computer memory for the moon missions.  When they were satisfied with a program they would say it was time to "put it on the rope."  

Here's an article on the women who built the rope memory (and the integrated circuits used in Apollo). This reminded me of the women's collective in Hyderabad that "wove" the ferrite core transformers for Farhan's BITX rigs: 

https://www.sciencenews.org/article/core-memory-weavers-navajo-apollo-raytheon-computer-nasa#:~:text=Core%20memory%20used%20metal%20wires,to%20create%20a%20particular%20pattern.

Here is a Wikipedia article on core rope ROM memory with some great illustrations: 

https://en.wikipedia.org/wiki/Core_rope_memory

The Rope

Other stuff of interest that I have spotted so far in the book Sunburst and Luminary -- An Apollo Memoir by Don Eyles:  

-- Not long before the fatal Apollo 1 fire, an MIT colleague of Don Eyles had a drink with Astronaut Gus Grissom.  Grissom unloaded about the poor state of the spacecraft, saying that, "What we have here is a Heathkit."  Grissom died in the fire. 

-- Eyles mentions the use of 6L6 tubes in analog audio amplifiers. 

-- MIT's Doc Draper used a Minox camera.  

-- When the Apollo 11 astronauts came back and were living for two weeks in an isolation chamber, NASA had bulldozers on standby to bury the whole thing ("astronauts, staff and all") in case some dangerous moon bug was detected.  (Is that true?) 

-- At one point soon before an important missile test, engineers realized that they needed an isolation transformer.  They did not have enough time to order one.  So they took an isolation transformer out of one of their soldering stations and used it in the missile.  It worked. Sometimes you just use what you have on hand. 

"Sunburst and Luminary" author Don Eyles was a Ham, a Hacker, and a user of Plywood who Understood Juju

-- As a kid, Eyles took a summertime shop class with W4LRO.  Eyles himself went on to get his ham license -- he was K4ZHF and was active for a while on the 40 meter and 6 meter bands. 

-- He writes of how the Apollo software acquired more "juju as labor and logic were poured into them." Juju. 

-- He describes the electronics lab in the MIT Instrumentation Laboratory: "If you had a private project you could sometimes get some simple milling done for a smile, and you could scrounge the odd resistor or capacitor... On the second floor there was a small "hackers shop" with a drill press, metal shear, a bending brake, and a few hand tools which was open to anyone, including software engineers. That was the first use of the term "hack" in a technical context, that I can recall hearing. I took the term as referring to the sometimes messy process by which perforations of suitable sizes were made in the aluminum boxes, or chassis, that were used for constructing electronic devices."  Indeed.  We hack.   

-- After describing the first integrated circuits, Eyles looks back at high school and notes that he and a friend, "after learning about truth tables, James Chambers and I had experimented with similar devices composed of relays mounted on a piece of plywood."  Plywood.  

  

More to follow on this book. 

The TEK 465 'Scope Used to Create Pong and the Apple II

Wow, this is almost enough to make me take another shot at repairing my TEK 465.  

 

How they Make Raspberry Pi 4 Single Board Computers

So, if the Raspberry Pi is a key part of your new "homebrew" rig, how much of the rig did YOU actually build? 

Antoine's Home Lab in Paris

Another very interestng lab brought to us by CuriousMarc.  

 

Curious Marc's Lab and Workshop

This is the guy who has done all the amazing videos on the Apollo communications systems.  And a lot more. This look at his lab is inspirational.  

There is so much to see here.  But a couple of things really caught my attention: 

All of the RF electronics in the Apollo spacecraft was made with discrete components -- the only chips in the spacecraft were in the computer.  And in the Apollo systems, they welded the discrete components in.  No soldering.  Welding.  That's hardcore.  That is how they got to the Moon.  

Curious Marc's YouTube channel:  https://www.youtube.com/@CuriousMarc

Back to the 1970's! Homebrew Keyboards! Don Lancaster's TV Typewriter

Even though it is outside my normal analog comfort zone, I really liked this video.  Farhan sent it to me, along with this note: 

--------------

As a kid, do you remember Don Lancaster's books? I learnt most of my digital electronics from him. I still have the 7 dollar video generator book on my shelf. He predates the Homebrew Computer Club. In fact, he is probably the reason for the HCC, because he put in the pieces that were used by others like the two Steves to build their own computers.

His most brilliant hack was to build a "TV typewriter" out of standard TTL parts that were just coming out in the surplus market. For $120, you could, if you build etched your own PCBs and managed to pry parts of fellow builder's dead fingers, build a circuit that, if you typed your name, it showed up on the TV screen! Never mind that dad wanted to get back to watching football or mom wanted the kitchen counter to be cleared out. Those days, parents had no appreciation for their kids being on TV, I guess.

In an earlier hack, he encouraged people through his articles in Radio Electronics to build their own Qwerty keyboard. With this in hand, you could, um .. um... well type something and sit back. There was nothing to connect it to. The fun thing was, there were no key switches available. You had to build those as well. Wind your own springs, make your own keytops, Once it was built, you could use a VOM to check that the ASCII bits corresponding to the key you held down would correctly show up on the 7 data lines. I guess the girls were surely impressed. You just needed to carry the power supply with +5, -5v, +12v, the keyboard itself, an ASCII chart and a VOM to school to show off.

Jokes apart, he kept building things and builds them to this day. His TTL cookbook and CMOS cookbooks were the goto books for almost all digital elecctronics hackers. It is a pity that no one acknowledges his knack. He has scanned in a few of his books on his 1990s www.tinaja.com.  Check  https://www.tinaja.com/ebooks/cmoscb.pdf

Why does it concern us? He is K3BYG, that's why.

Watch this https://www.youtube.com/watch?v=b-bFV8fHekk

- f

-----------

 So many things from the video resonated with me: 

-- The importance of building and testing, stage by stage.  The narrator admits "I might have screwed that up."

-- Homebrew keyboards!  Make your own keyboard springs you pathetic appliance operators! 

-- Wood box. 

-- Origins of ASCI

-- The scary 1970s.  Indeed.   I started High School in 1972. 

-- Schematic errors!   Oh the humanity!  Erratas. 

-- Appeals to the Digital Gods. (Not as powerful as The Radio Gods.)

-- A Gimmick Twin Lead. 

-- "So many different disciplines went into building this thing..." 

-- A taste of the home computing revolution of the 1970s. 

-- Farhan is right -- he was K3BYG.  But that call now seems to belong to someone else. 

Don Lancaster's unofficial autobiography: 

https://www.tinaja.com/glib/waywere.pdf

Clearly, Don Lancaster has The Knack! 

The Vacuum Tube's Forgotten Rival: The Magnetic Amplifier

The video above shows one application of the principal, but be sure to check out the IEEE article:  

https://spectrum.ieee.org/the-vacuum-tubes-forgotten-rival

An Interview with Paul Lutus (Audio)

https://corecursive.com/remote-developer/

Thanks to Bob Scott KD4EBM for alerting us to this wonderful interview. 

Another M^3: The Michigan Micro Mote

Move over Michigan Mighty Mite and Mate for the Mighty Midget.   There's a new M^3 in town.  And it is SMALL. 

Hack-A-Day had an article on this today, and while it seems only tenuously connected to ham radio, I found it intriguing.  

Check it out.  Who knows, someday people may be operating in "dust mode":  

https://hackaday.com/2021/10/04/snails-sensors-and-smart-dust-the-michigan-micro-mote/#more-498450

The Woz on Homebrewing and The Right to Repair

There is a lot of wisdom and history in this Cameo video by Steve Wozniak.  

Thanks to Chuck KE5SPY for alerting us to this.  

Here a good BBC article that summarizes the Right to Repair issue and Woz's involvement.

https://www.bbc.com/news/technology-57763037

The Woz has The Knack.  

Marc Verdiell Has The Knack

Here is Marc Verdiell, the "Curious Marc" who repaired the Soyuz Clock (shown in yesterday's blog post).  

Really cool.  Many SolderSmoke fans will completely understand Marc and his passion for 
electronics.