Wednesday, July 2, 2008

Doing what I like

I occasionally browse through Elektor magazine. I've always been interested in gadgets especially the electronic ones and although I haven't earned a dollar building circuitry for a long time now, I've tried to keep up with what's been happening in electronic design. In the late 70s I wrote a BASIC program to convert circuit diagrams into wirewrap instructions and although I sold a copy to a small electronics firm I never pursued it as a marketable product (fool me!). I was never willing to spend the ten of thousands of dollars needed to buy an auto wirewrap machine and my vision of what I wanted to do never got to the "make a living" stage. So most of the time I was content to manually type in the circuit diagram to my program and let it calculate the length and order of the wires and then I could manually wrap my little circuits and get on with the fun of testing and debugging them.

I've referred in another post to Louis Savain's Universal Behaviour Machine. He's been getting heaps of flak in his comments posts, not the least because he doesn't seem willing/able to move beyond rhetoric about why a UBM (parallel processing) is a better paradigm for computing than a Universal Turing Machine (serial processing). One of the comments caught my attention. It suggested that Savain's UBM is "nothing more" (I love that phrase, it immediately alerts me that there is something to look at) than VHDL. "What's VDHL?" says I. Quick Google throws up a wealth of info and links including a series of articles in Elektor on FPGAs which I had glossed over. FPGAs were always attractive but the devel kits were typically thousands of dollars and not for doodlers like me. But then I saw an ad for a really cheap evaluation kit. For $39 I don't care if I blow it up, it's worth trying out.

So the web of ideas goes something like: no UBM yet -> make one -> how? -> modify an existing micro-core -> how? -> learn how to build/install/modify a micro-core in an FPGA -> how? -> buy a cheap eval kit -> where? -> aha! Avnet just released one -> order it -> learn about VHDL -> how? -> read on-line stuff -> note that some people are using Forth to program FPGAs -> how? -> learn Forth -> install a Forth micro-core on FPGA and try it out... and so on and so on.

But the best news for me is that I can use all those years of building logic systems once again. I already know about sync pulses and NOR/NAND logic and multiplexed buses etc. etc. It's quietly gotten a whole lot easier and cheaper to implement this stuff. My last attempt was an ASIC in the 80s, really expensive to design, test and make.

And it's something I like doing.

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