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Building an Apple-1 From Scratch — Just Like Woz
Lucas123 writes "This year at KansasFest, computer fans from around the world gathered to celebrate the Apple II — the computer that put Apple on the map. But the Apple-1 (a.k.a. the Apple I), the machine Steve Wozniak invented and first demonstrated at the Palo Alto Homebrew Computer Club in 1976, has always been near to my heart. In attendance at KansasFest was Vince Briel, who created an authorized reproduction the Apple-1 and showed others how to build their own. 'As a regular KansasFest attendee (and the conference's marketing director), I was one of his students. Follow along as I assemble a fully functional Apple-1 clone.'"
...he will attempt to talk to women!
paintball
It was made in 1976. That's 33 years ago. Any relevant patents should have expired about 13 years ago.
There's something about it that sticks in my craw.
It's "an antique" computer. It's a computer of historical significance. But to require authorization to recreate something that was essentially made of "off the shelf" components? The only thing I can imagine would require authorization would be the right to put an apple logo on it, and they give away apple logo stickers with just about everything Apple sells. Oh yeah, and the BASIC ROM, but I am sure someone could start an OSS project to create a compatible Apple ROM that doesn't infringe on the copyright.
I was hoping for something more in-depth than just soldering stuff on a prefabricated PCB. That's a no-brainer.
Now, go through the steps of doing a schematic, then translating it into artwork and etching the boards and it might be a pretty interesting article.
There is a book (linked in the article) called "Apple I Replica Creation: Back To The Garage" by Tom Owad that basically walks you through the construction of the Breil Computer kit, as well as a crash course in programming it in assembly and BASIC as well a a crash course in electronics design. It is a good read.
All-in-all, this is nothing really special. Anyone who buys the kit can solder it together. I believe he also has fully constructed boards as well. This seems more like an advertisement than an actual story.
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To get the true Woz experience have your best friend steal thousands from you and then lie to you about it.
Erm, haven't we more or less been doing that for around two decades now? I mean granted, the design has improved...
"linux is just DOS with a UNIX like syntax" -- Galactic Dominator (944134)
>Apple //e
Nah. A plain, straight Apple II. Not even a +, just a II. (OK, ][).
And without the changes at the Rev 7 motherboard that took the purple tint away on the text.
OK, I'll settle for an emulator that runs full-screen on linux or FreeBSD, with the purple-tinting, and with a parameter for how fuzzy my television is . . .
For those under--oh, yikes!! can't admit *that*, the ][ had a purplish tint on most color displays because the color subcarrier was still present. In rev 7, this finally got supressed while displaying text--whether in text mode or the 4 lines of text in mixed mode. On top of that, at a 1mhz clock, with characters displayed at the same speed, and seven horizontal pixels per, *they* were coming at about the colorburst frequency (seven Million pixels/second, right about twice 3.575949 Mhaz when they alternate off and on--and if memory serves, the color carrier & the pixel clock actually came from the same clock [a 14mhz??? it's been a while]).
The multiple colors in hi-res also came from tickling the color carrier--seven pixels/byte, with the eight being used to slightly shift the timing of the pixels, causing color change as the pixel rubbed the color subcarrier).
hawk, who has some //e's in the garage, but wants to set up a plain old ][ to run a model railroad.
I have a near-mint condition Sinclair ZX Spectrum 48k safely stored away somewhere - I haven't powered it up in years... The reason is because they were designed quite cheaply: You have a 9V power pack which is both regulated down to 5V for the majority of the logic and in an inspired piece of electronics, it is also inverted for the +12V and -12V power lines with very few components. Why is that important? Well, early DRAM, as used in the Spectrum, required those power lines too. However, there is a slight failure mode which claimed the life of my first Spectrum: The inverter regulation could fail and the memory/logic is zapped with 40+V before it fries and takes itself out of commission.
As a result, there are relatively few operational ZX Spectrums around, despite how massively popular and successful they were.
My biggest lament is that I have lost the ZX Printer - I think it accidently was left behind in the last home move ... I still have 6 or 7 rolls of the aluminiumised silver paper for it.
Ahh, fond memories of the smell of ozone and burning metal while it did print out for you...
No sig. Move along - nothing to see here.
I'm not suprised he put the CPU in backwards if he can't tell the difference between an L.E.D. and a D.C. power connector...
I reserve the right to be wrong.
In high school I took a class like that, except it was at a much lower level - we actually worked towards the design of a 4-bit microprocessor based on discrete logic gates and flip flops. We started with simple AND, OR, NOR, NAND gates, the different types of flip flops, moving to using Karnaugh maps to design logic, and covering simple CPU design - things like bus registers.
I remember one week's project was to design and build a hex matrix keypad - it was pretty neat to build something like that out of 74-series logic on a breadboard and actually have it work. I used a string of three inverters (1/4 each of a 7404) with the output of the last inverter feeding back into the input of the first, as my keypad's clock generator. The teacher was surprised it worked, and even more surprised that the 74-series logic was running at 24MHz (this was 1988, and the fastest computer we had in the lab ran at 6MHz).
I also remember building a 7-segment LED display driver circuit, and things like adders and shift registers.
I think the only reason our school was able to offer this class was because there was a State program that offered grants to high schools to improve their electronics labs. The total grant money available for the entire state was $150,000. We were told that the electronics teacher at the school was the only applicant for the grant program and our school had been awarded the entire $150,000. Needless to say, the electronics lab at my high school was better equipped than some university labs I've seen.
Putting moderation advice in your
The inverter regulation could fail and the memory/logic is zapped with 40+V before it fries and takes itself out of commission.
As a result, there are relatively few operational ZX Spectrums around, despite how massively popular and successful they were.
Actually, what happens is that one of the 4116 memories for the lower 16k fails by shorting its 12V line to ground. This kills the chopper transistor in the very simple inverter. The key symptom of that is flickery garbage with a distinct stripe in each square on the screen and no colour. The failed chip always seems to stick the output high, and the rest of the memory produces random values. The video is greyscale because the 12V line is also used to supply the colour modulator. It's trivially easy to fix this - find and replace the failed memory chip, and then replace the ZTX650 chopper tranny.
As for there being relatively few operation ZX Spectrums around, this is just plain untrue ;-)
http://www.midatlanticretro.org/1M/index.shtm
That might prove kinda fun...?
Imagine a Beowulf cluster of those!!
Light travels faster than sound. This is why some people appear bright until you hear them speak.........