Logan’s story about electronics!

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Logan’s story about electronics!

Hello, I’m Logan Greer! I'm currently 16 years old and some of you might know me from the Apple ll enthusiasts group on Facebook for others that don’t, hi!

I thought I'd tell my story for those that want to know, so going all the way back to childhood years, I always loved taking apart electronics, and trying to figure out how they worked, I'd disassemble clocks, break down VCRs and DVD players, electronic toys and TV sets, just to see how there parts communicated to the others to get the technology to work like it did, I also would build little cardboard projects, If I didn't have the real thing I'd build it out of cardboard to match it, haha! But that was just how my mind worked and still works when looking at technology, hence the term (work with what you have), and I had tape, paper, cardboard and scissors.

 

So then moving forward many years until March 2018, I was about 13-14, I had been attending my local middle school, and we had a computer lab with windows 7 desktop computers and our class worked on class projects in there. So I had a friend named Alex, and I can't remember what led to it but he told that there was an old crap Mac computer in the library, and I didn't believe him so then later on I went into the library and looked around and lone behold, there was an ORIGINAL 1984 Macintosh computer that our librarian had owned since she originally had bought it!

 

So then after learning what it was i went home and researched as much as I could about that computer, and I thought that the Mac was the company's first product at that time. While doing all of that research I learned that, there was the Apple ll computer that came out before it, and when I saw that photo of the Apple ll, I instantly fell in love with it! So I spent MONTHS researching how it came to be who made it, how did it work etc. Then in August, I acquired my first EVER Apple ll Plus computer, and the experience was amazing! 

 

Then skipping forward again to May 2019, I was then (15) and had decided to try and make my own Apple ii Rev.0 replica board, spending a 2 weeks to a month total. I ended up highly successfully doing just that! I also posted that on the apple ll enthusiasts Facebook group for those interested!  

 

 Also moving forward 3 months ahead to August 2019, I decided to show up for my first ever old technology convention which was VCF West 2019 at the computer history museum in mountain view, CA! Which is where I met, wendall sander, Daniel kottke, Corey Cohen and Lee Felsenstein!! That event became the most memorable time of my life, also wendall was the one that convinced me to join this group! But skipping forward to now, I'm currently taking on the challenge of building my own Apple-1 replica and currently it's going great! (Also I have 2 5300uF 15V caps I want to get rid of if anyone wants.)

 

 So anyways with my first ever post (being this one) I'd just thought I'd share my story! P.S. I am not sure how to add photos to this forum post but if you guys know that would be great! 

Best, Logan

 

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Welcome to AppleFritter Logan

Welcome to AppleFritter Logan.  I've seen lots of your posts on Facebook over the last couple of years.  Glad to see you've joined the Fritter group finally.

I'm not on Facebook so you will never see me posting anything over there, though I wish more of the clan that hangs out over there would join this group.

I've seen you take on some ambitious projects, one being the Apple ][ Rev. 0 boards, and as of late, the Apple 1.  I think you'll find that obtaining the parts for the Apple 1 is becomming a challenge as of late,   Not so much with getting "original date" parts, but the parts for them in general.  -especially those pesky 2501's among a few other IC's.  You will be challenged building one.  A few folks in China tried selling them at a high dollar amount for a while on eBay, but I don't know how successful they were in getting the price.  If you're patient with finding the parts, you should be able to build one up for a few hunbdred dollars.  The keyboards are ghetting hard to find unless you use an Apple ][ keyboard with a modified plug on the end.  I'm sure you've already been down that road.

Anyway, welcone to the group.  I hope you are able to scope out this site, visit some past posts, etc, maybe pick up a few new-to-you pointers.  Enjoy!

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Parts

Thanks for the welcome, @macnoyd! Actually I have had good luck with finding the parts for an Apple-1 board. My goal is to do exactly what Apple did in 1976, by that I mean sell an Apple-1 board for $666.66 so far the ABSOLUTE only parts that where hard to find cheap is the blue caps and the 2504V ICs and the 2519 IC, and so far I was able to get almost 98% of the parts for cheap at unicornelectronics.com, I haven't spent over $250 too get the parts yet. So that's FANTASTIC!!

Best,

Logan

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Welcome to Applefritter, Logan !

Smart move of yours to start with 1970s technology. This is the way to truly learn how digital electronics work from the ground up.

All the kids and teens today who dabble around with Arduinos or Raspberry Pi are smart, too, but they waste their time with tech that is too far above their heads. No way to really understand these hi-tech items. No way ! They are up against 1000's or even 10000's of man-years of design and development work in these chip sets and in all the software tools and operating systems needed to make apps for them, consisting of 10's of millions of lines of code no single person can ever understand. "Experts" included.

I'm not saying that these kids and teens don't learn anything by building projects with Arduinos or Raspberry Pi, they eventually will learn how to write code and how to run the toolchain, but that's about all of it. They can use the underlying hardware and software, but never could design any of it.

The simpler 1970s tech is so primitive compared to what we have now that you can literally understand every gate, and flipflop, and bit in the machine.

Even building a digital clock from TTL ICs as was en vogue in the early 1970s gave great insight into how digital electronics work.

But always keep in mind that the real world is analog, and analog is difficult. You can make more money in analog electronics (or, more specific, analog IC design) than in digital. RF / Microwave IC design and application engineers are also being paid very well, if not even better. But avoid to work for a defense contractor ... they slice and dice the task at hand such that nobody gets the whole picture on how their technology works. Same with the guys who design the nukes. So if you work for those outfits you may become an expert for a small piece of classified and proprietary technology owned by the MIC, and once sitting in that trap,  it's hard to get out and get better pay. Not being able to ever talk to anyone about the prior work you have done compounding the problem. It's called the "Raytheon disease". Avoid it. A friend of mine went to the same university as me and he dared to specialize in RF/microwave. He then learned his trade at a big corporation (the sort thats builds everything from ICs to nuclear power plants) and once he was really good, and could make his stuff work the first time, joined a microwave IC start up as an employee  (think radar door openers, radar in cars, ...) He now is a multi-millionaire and retired at age 55. I designed analog ICs for some of the big names in the field and did not get that rich, but I'm OK and retired at the same age, too. While all those I know from my university days which went into digital or software, still have to run in the hamster wheel and were not even able to pay back the mortgage yet. Well, McMansions, all of them, but not much net worth, really.

 

Bernie

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Interesting story

Interesting story, @unclebernie!

 

I also agree with you that me learning about 1970s technology first was a smart move because I actually indeed was able to start understanding how that technology worked! I started learning binary, hexadecimal and decimal conversions, logic gates, resistors, transistors and I/O, memory locations, and shift registers!! 

Which has made me understand things like the apple-1 and Apple ll a lot easier, learning those things kind of helped me breakdown how the circuits worked! Wozniak's design is just outstanding, his layouts and the parts he abused to get the results he needed, there was a story he was telling in an interview and he was talking about the Apple ll color development, and he said  "I had leaned about analog TV electronics in high school, and I knew I'm my head that I could use a little $1 chip, (I think that was the 74LS259 or a 9334)  to get color on my TV set, because back in early days at atari when I was prototyping my breakout design, I was sleepy and I was kinda dosing off and I remember me seeing a black and white television because that's all Atari had on the floor at the time, and I saw Mylar tape was that was colored, and I started thinking about (faintly saying) color, then one thing led to other and I had the Apple ii." THAT STORY just blows my mind, it just REPRESENTS conservation and creative thinking!! Now a days with the  raspberry pi and the new hobbyist types of projects. Not that they're bad either but I feel I wouldn't learn about as much with those than an Apple ll.

Best,

Logan

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The greatest achievement of Woz ...

... in terms of truly brilliant engineering is the Disk II subsystem for the Apple II.

 

I thought I had understood it since 1978 or so, but when I really took it apart this year and got to the bottom of it, I stood in awe.

 

How the so-called "Woz machine" (this is the small state machine on the Disk II card) interacts with the low-level driver software is absolutely mind-boggling.

 

Over all these decades it has been studied again and again by many curious people and a lot has been written about it how it works, but how it really works was never written up correctly. There are so many subtleties hidden in it, down to exploiting some peculiar quirks in the 6502, that it is hard to understand how he could have pulled that design off with just a brain, a pencil, and some sheets of paper.

 

In my eye it is a true masterpiece of minimalistic design and out-of-the-box thinking: nothing can be taken away, and nothing needs to be added, and it works fine and does its job with minimum hardware expenditure, replacing all the hardware that may be run at slower speeds by software.  Just as an another important historical example, Mike Cheiky (founder of Ohio Scientific) in his floppy disk controller used even fewer  ICs than Woz  did, and his design worked, too, but  Mike took the simplification a bit too far ... pressing an ACIA into service as a FDC, well ... let's say ... kinda works, out-of-the-box thinking, sure, but ... if you ever have the chance to see an OSI with floppy disk at a VCF, try it out and see the consequences yourself !

 

Other than the Disk II the Apple II was not that super innovative, IMHO. For sure it was the most innovative microcomputer design among the "1977 Trinity", Apple II, Commodore PET 2001, and Radio Shack TRS-80, the three which really started the homecomputer craze, but at the time the Apple II came out, Atari already had the  ANTIC, CTIA, and POKEY full-custom chips in design, and when the Atari 400/800 based on that chipset were presented on the January 1979 CES, every other 8-bit micro on the market was practically obsolete over night in terms of graphics and sound capabilities.

 

But ... the Apple II with the Disk II soldiered on and Apple probably made more money with it than all the other 8-bit microcomputer manufacturers combined (many actually lost money and how much profit was made with the C-64 is questionable, snarky people claimed Commodore never made any profit with them, but nobody ever was able to untangle the maze of companies that Commodore was). There are some subtle differences between a hobby / gaming computer and an office computer.  Apple II with Disk II and some cards added in the slots was a nice and quite capable office computer for small businesses at a good price point. The IBM PC aiming at the same market was ridicolously expensive at first but then proceeded to gain momentum, PC clones driving prices down, and took the office market away from the Apple II. The more capable video game consoles that appeared in the early / mid 1980's eroded the gamer market for all micro computers and at about 1988 the typical 8-bit homecomputer was dead and most got tossed away or went into attics or storage units.

 

R.I.P. the "Golden Decade Of Home Computers", 1978 - 1988 (my opinion, not general concensus, but I don't care, I closed my business in 1988 due to lack of demand for Atari add-ons, but was already financially independent due to the success of my products).

 

Here is a challenge for you: explain how the linefeed / scrolling mechanism in the Apple I works on the hardware / gates / state machine level. If you really understand it, you are damn good.

 

Good luck and have fun with those vintage computers from the "Golden Decade" !

 

Bernie

 

P.S.: no offense, but IMHO the mylar foil story is BS as far as the influence on the Apple II goes. I remember that back in the day they put colored translucent mylar foils on the B&W picture tubes of some arcade machines (like BREAKOUT), to get the impression of a game in color, but there is NO way this leads to how the design of the Apple II color generation works.

 

I think that what really happend is that Woz might not have intended to have color in hires mode at first, but once he had the prototype wrapped up and hooked to a NTSC color TV to check out his lowres color graphics, he may have discovered that there are nasty color artifacts in the text mode (and in the hires mode). So he proceeded to declare the hires mode to have four colors. An example on how a "bug" can be turned into a desirable "feature" customers are willing to pay a premium for. Using the still unused 8th bit in a graphics byte to have an additional selectable 0/90 phase shift of the pixel clock is the next consequential step, it takes almost no added hardware, and so he had got six colors (to be precise, four colors and black and white, the latter to not being "colors" in the strict sense).  This, however, is just my own conjecture what really may have happened, based on the evidence at hand. IMHO whoever wrote that book or article up where you got it from was a journalist unable to see the contradictions and the holes in the story.

 

The narration with the 74LS259 or a 9334 having to do with color generation is utter BS, too - - - these are the "soft switches" that turn graphics modes and other things in the Apple II on and off, quite another Woz innovation to exploit these parts using only the addresses and none of the data bus to control the switches, which enables a lot of tricks being played in the device driver software and leading to the DISK II bag of wonders / trickery).

 

I think what Woz really may have wanted to refer to in that book or article is his way to generate the many lores colors, which is truly innovative  - - - I never saw any similar circuit before Woz used it, and everybody else in the mid 1970s wanting to produce a multitude of NTSC colors worked with delay lines made out of a chain of gates, which is temperamental and awkward and more a hobbyist thing. The way Woz generates the many lores colors is really brilliant out-of-the-box thinking, is robust against IC parametric spread, is temperature stable, and requires no adjustments on the assembly line (except that little trimmer on the tank circuit, which is cheap and quick to do).

 

I wrote a comment on this forum that goes deeper into the Apple II color generation and the NTSC way (and the Woz way) to do the color encoding / color signal generation:

 

https://www.applefritter.com/content/apple-ii-composite-out-lcd-tvgood-quality-choices

 

The bottom line is, Woz turned all the reasoning of the NTSC comittee upside down to get color without even having a color encoder anywhere. This would be a RGB matrix, producing color difference signals, some filters, a color subcarrier oscillator, a quadrature modulator, even more filters, and some resistor matrix adding all the signals together. Woz did not need ONE item of that list. All dispensed with. Zero costs added. This is the genius for which he got a patent on the Apple II.

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Wow absolutely amazing! I

Wow absolutely amazing!

 

I love people giving all their knowledge about Woz, and how great he is at designing circuits and making prototypes FROM scratch! His apple-1 and Apple ll designs are truly a testament to how far technology has grown since then! Thanks for the info at @unclebernie!

I will also try and figure out that stuff about the Apple-1 that you challenged me about! 

Best, 

Logan

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On the value of vintage electronics -

Logan,

 

 it is very rare that young people like you venture into researching our technological past. Be assured you will have a lot of fun with it, and learn a lot, which you may be able to leverage for a later career in electronics.  The foundations of a house must stand on solid ground, bedrock, and not on a wobbly morass. I interviewed many young engineers who had applied for a job and most of them had no solid foundations, despite they came from reputable universities. There were a few exceptions, though, and these were hired and later had a good career. Almost all of the candidates that were hired  had been electronics hobbyists or ham radio operators in their youth, and most had tinkered with early microcomputers, and although I never asked that question, I suspect that their vintage hardware (and software) was handed down from father to son. How else could it happen ? Finding an old Apple II on a flea market ? Unlikely, but may happen in some cases.

 

My age group has witnessed a great successful run in electronics that lasted 50+ years (I was born the year when the first TTL ICs came out, so I missed that part). We were teenagers when the microprocessor was invented. We saw the first microprocessor based electronic arcade games - my favourites were Seawolf, Shootout (name correct ?) (both B & W), Galaxian, Pac Man, and Donkey Kong (all 3 in color).  Prior to the microprocessor there were only electromechanical pinball machines, which definitely were a 1960s thing. Then came the home computers which had their "Golden Decade" just to be obsoleted because their market went away as it split into pure office computers (aka "PC") and pure game consoles.

 

The advantage for us was that, if we had enough interest in the topic, we could see the technology grow slowly and organically, and everything made sense. So our foundations grew slowly and are solid. Any young person today venturing into the field without any prior exposure only is able to see the surface, the tip of the iceberg and if improperly prepared by colleges or universities will not have acquired the foundations needed to do the job.

 

The modern SMD parts (especially the fine pitch ones) are a further obstacle, although hand assembly with them can be done, it requires a specialized workstation with special tools costing thousands of dollars. Back in the day all electronic components had leads und the pin pitch was only 0.1", easily handled and soldered even for kids, who typically do not yet have fully developed fine motor skills. Today, hand-assembly of modern components requires said special workstation, very good eyesight, and the fine motor skills of a watchmaker. I can't do that and never could. Always had a lady in the lab who had the fine fingers and the skills to operate these tools.

 

Working with vintage electronics avoids these complications and gives insights that are valid even today. The technical foundations never go away and never become obsolete: physics, mathematics, boolean algebra, logic. While colleges and universities teach all these foundations, IMHO they teach it the wrong way, out of context of the real technical application, and unless the students acquire these missing links themselves (or have had prior hand-on experience tinkering with electronics), they can't do the job, and today's corporations are less and less inclined to hire such candidates, as it takes too much time and effort and money to make them productive.

 

Now about the Apple I linefeed / scrolling logic analysis task, I give you a few hints so as to encourage you:

 

1. get the schematic of the video section from the Apple I user manual on a magnified printout so you can make notes on the parts and signals.

2. get a good TTL databook (or download their datasheets)

3. note that the "cursor" position lives in the IC 11b, the 2504 at schematic position A6

4.  at schematic positions A-B 1-2 there is a cluster that handles the character handshaking with the CPU section

5. that cluster is a state machine that controls the linefeed and scrolling

6. the state machine takes and makes various control signals - find out what they do first, then analyse the state machine

 

One you have understood how it works, write up a nice description even we can understand ;-)

 

Seriously, this is a task worth doing, and you could make a great contribution to the Apple I scene.

And being a young person, you probably have more time available then us.

 

Good luck !

 

Bernie

 

 

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Thanks for that @unclebernie!

Thanks for that @unclebernie! 

It's nice to know that my choice to pursue this division of electronics is a good move! I'm gonna go ahead and take a look at the schematic now and see if I can look for what you're talking about!  

Best,

Logan

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