This evening I received a phone call from a California phone number that I didn't recognize. I was busy at the time and let it go to voicemail. About 10 minutes later my phone beeped to announce an incoming email.
It turned out to be from a sales rep from a board house wanting to know why I "stopped" ordering from them. The answer is easy: I placed one order with them, and they screwed it up. Then they argued with me about whether they'd screwed it up when all they had to do was compare the Gerbers with the board they delivered. There's an obvious difference when the pads for an SMD are missing, leaving only the stubs of the traces that are supposed to connect to them. Especially when the customer is telling you where to look.
Oh, but they've "invested $45 million" in the last 10 years upgrading their equipment and carry ISO this and ISO that certifications. Their new brochure looks nice, but did they also replace the customer service people? Reputations are easy to tarnish and hard to rebuild, and I have no incentive to give them another try.
(Also, their prices are almost double that of the European board house I've been using, and their product is gorgeous).
Experiments with the world's first microprocessor
and other electronic explorations
Hi,
ReplyDeleteI'm not sure where to post this but here will do as I can't find a email address to contact.
Anyway I've been looking for people to ask about processor schematics and well designing a process. The catch is I want it to be entirely open source, which seems to result in having to design it from discrete parts all the way up. Except up to the RTL level I could use OpenRISC 1200 which makes things easier at least.
So yeah any help you can provide with that would be appreciated.
Thanks!
If I'm not mistaken, the Intel 4004 schematics are now available under the Creative Commons Share-Alike Non-Commercial license. It's a small design, with only 2200-some components compared to the billions in a modern x86 chip, but its dynamic logic is also an old technology.
ReplyDeleteI'm no expert at processor design. My thinking is that for any reasonable processor design you'll need to move up from the discrete component level I'm doing to at least small- or medium-scale integration (CMOS or TTL gates) or the project will quickly get too big for anyone to want to undertake. Even then, the cost of a design change can be painful.
At some point I'd just throw in the towel and use an FPGA programmed in Verilog or VHDL. There was a writeup in the Xilinx journal about someone who has implemented the Cray-1 design in a Spartan 3E-1600 FPGA, and I think it even runs at about the same speed as a real Cray-1. Digilent sells that board for less than $250 and the development environment is free, so the entry cost isn't that high.