[GreenKeys] Re: simple schematic drawing

[Craig Sawyers]

> http://www.expresspcb.com/
>
> They have a simple-minded PC layout program

Problem with all the freeware from PC vendors is that the printout is
doctored so that you can't use it to produce your own artwork - it always
has a background grid.  So the only way you can get a PC made from your
design is to use the vendor.  Which is OK I guess, but it cramps your
options somewhat,

By far the better option is to use a freeware version of a real program.
The one I use is Cadsoft Eagle Light (Eagle = Easily Applicable Graphic
Layout Editor), although there are others.  Eagle is a fully functioned
schematic data capture and autorouter, with the only restrictions being that
you can only have one schematic sheet per design, that the board size is
limited to half Euro-card (around 4" x 3.25") and two layers maximum.  Now
even with conventional pin and hole components you can cram a lot onto a 4"
x3.25" board, and with surface mount it is a huge area.  BTW the fully
featured version without these restrictions is $1200.

You can download it from http://www.cadsoft.de/.  If you want it fully
supported, and with a set of printed manuals you need to register it for
$49 - although this is not essential.

I also found a really cheap place for producing PCs, where they take Eagle
output files (so you don't have to worry about converting them to Gerber -
although Eagle can do this anyway).  They are
http://www.olimex.com/pcb/index.html, and will produce a single PC in
Eurocard format (so you get two Eagle freeware boards), two layer with
solder mask and screened component locations for $26.  Haven't used them
yet, but I certainly will when I next need a prototype PC.

Craig