[time-nuts] RS232 / GPS interface/prototyping board

[Orin Eman]

On Wed, Jun 22, 2016 at 3:14 PM, Nick Sayer via time-nuts <
time-nuts at febo.com> wrote:

>
> > On Jun 22, 2016, at 1:33 PM, Mark Sims <holrum at hotmail.com> wrote:
> >
> > The value, quality, and turn-around from all these places is amazing.
>  In the olden days, one was paying $50 a square inch for a single prototype
> board with 4 week turn-around.
> >
>
> Not to turn this into the “Four Yorkshireman” sketch, but in the olden
> days (which by my reckoning were maybe only 10 years ago) there wasn’t
> reasonable hobbyist access to PCB CAD software either - like EAGLE or
> Altium or KiCad or the like.
>


Easytrax - I used it at least as long ago as 1998 because that's the
copyright date on the boards I had made at AP Circuits.  The boards weren't
cheap, I seem to recall in the order of $100 for a couple of double sided
boards with plated through holes and no solder mask.  Of course, Easytrax
is a DOS program and PCB layout only, but it did the trick.  You can still
make it work under a DOS emulator.  I used to call it 'vi' for PCBs given
the way you gave it commands from the keyboard.  I still remember "pt" for
place track...

I use Eagle now.  It's not much better for PCB layout, but at least it has
the schematic editor.  I've tried KiCad at least twice, but find no
advantage over Eagle and keep going back to the Eagle free version.


>
> When I was a teenager (mid 80s) I tried making my own PCB with clad board,
> an etch resist pen, that nasty brown acid and the smallest drill bit I
> could get my hands on. This was a single-sided board - I had absolutely no
> way to line up a two-sided design even if through-hole plating would have
> been an option (of course, it wouldn’t have). No solder resist, no silk
> screen.
>
> It was a disaster. Even with a drill press I couldn’t line the DIP holes
> up closely enough to mash a chip in without bending the leads to hell and
> gone.
>


BTDT too.  I used a 1/16" drill bit and a hand drill.  I'm sure the drill
bit wandered...  For home etched boards, I now use the MG Chemicals
positive resist boards.  If you have the CAD program print the pads with
the holes when you make the transparency, and hold the board just right
under a drill press, the board will self-center under the drill bit!  I'm
sure the MG Chemicals boards cost more per square inch than the Chinese
suppliers, but I can have a single sided board exposed, etched and drilled
in a couple of hours once I have the design.  If I'm going to home-produce
a board, I design it with two layers, but use the top layer as little as
possible and use wire links for all tracks on the top layer... obviously I
have to be careful where I put tracks on the top layer when doing this.

Orin.