The Old Days
Back in the pre-computer CAD days, PCBs were designed and laid out by hand using adhesive tapes and pads on clear drafting film. Many hours were spent slouched over a fluorescent light box, cutting, placing, ripping up, and routing tracks by hand. Bishop Graphics, Letraset, and even Dalo pens will be names that evoke fond, or not so fond memories. Those days are well and truly gone, with computer based PCB design having replaced this method completely in both hobbyist and professional electronics. Computer based CAD programs allow the utmost in flexibility in board design and editing over the traditional techniques. What used to take hours can now be done in seconds.
PCB Packages
There are many PCB design packages available on the market, a few of which are freeware, shareware, or limited component full versions. Protel is the defacto industry standard package in Australia. Professionals use the expensive high end Windows based packages such as 99SE and DXP. Hobbyists use the excellent freeware DOS based Protel AutoTrax program, which was, once upon a time, the high-end package of choice in Australia. Confusingly, there is now another Windows based package also called AutoTrax EDA. This is in no way related to the Protel software. This article does not focus on the use of any one package, so the information can be applied to almost any PCB package available. There is however, one distinct exception. Using a PCB only package, which does not have schematic capability, greatly limits what you can do with the package in the professional sense. Many of the more advanced techniques to be described later require access to a compatible schematic editor program. This will be explained when required.
Electronics Equipment Repair Center
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