Hi, Don -
I thought it cost the seller something to do that. You published an article concerning the break-even cost of selling on eBay ($30,$50,?). Since they are worth very little (presumably
Like I said, expensive for something with a total worth of around $10 (USD). Old motherboards are not hard to come by in my line of work.
A bit of both. The CPUs themselves rarely gets built due to the complexity (number of wirewraps & amount of soldering) of their design. Most of my CPU design are merely simulated on Digital Works. Just knowing that i've implemented a working schematic and not just Verilog or VHDL is good enough for me.
Microprocessor projects are built more often. Usually test jigs such as function and pulse generators for testing the performance of stuff I design profesionally.
I'm currently building a CPU based on a Transport Triggered Architecture. Since it is nothing more than a glorified bus it is easy to build. And I can implement each functional unit on a separate veroboard.
I've been planning to do just that for five years now. Never have the time. Most of my early design are pen-on-paper I did during lunch hour. More recent designs are on the PC (Notepad) I did while waiting for programs to compile. So the more recent ones are easier to publish on the web.
I do have a web site at slebetman.homeip.net just haven't gotten around to putting my designs on it yet.
Yeah but when you're trying to figure out stuff like why the add instruction fetches data from the wrong register it really helps if you don't have to worry about refresh and can clock the circuit down to 1 instruction per minute.
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