Building an Apple-1 From Scratch — Just Like Woz 99
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.'"
Authorized replica? (Score:5, Informative)
It was made in 1976. That's 33 years ago. Any relevant patents should have expired about 13 years ago.
There is a book (Score:5, Informative)
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.
Re:"Authorized" reproduction (Score:5, Informative)
n00b (Score:1, Informative)
He put the 6502 in upside down. FAIL, uninstall.
Re:That is a great project (Score:3, Informative)
>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.
Re:"Authorized" reproduction (Score:2, Informative)
Re:That is a great project (Score:4, Informative)
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 ;-)
Re:Authorized replica? (Score:5, Informative)