How where circuits drawn during the 80's

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Robin Mitchell

Joined Oct 25, 2009
819
Hi everyone,

I have always wondered how this was done before computers where common place. How where schematics and PCBs designed before the use of computers?

If schematics where drawn by hand then where stencils used (like symbol outlines)? Where PCBs routed by hand and every pad draw with pen on some transparent film? How was it all done :S ?

All the best!
Robin
 

MrChips

Joined Oct 2, 2009
30,821
This past week I was looking at an electronics design handbook from the 1960s with lovely drawings and text that was right justified.

Similar thoughts of how did they do this in those days came to mind.

As far as I can tell, all the drawings, labeling and math equations were drawn by hand using Leroy lettering templates or similar.

My guess also was that the typesetting was done by hand using lead blocks (in reverse imaging!).

And I did not notice a single typo error!
 

Wendy

Joined Mar 24, 2008
23,429
By hand was how I did it in college, pencils being the first word processor. You developed a knack for drawing back then.
 

crutschow

Joined Mar 14, 2008
34,460
When I went to college (well before the 80's) I had to take two semesters of mechanical drawing where you used T-squares and templates at a large drafting table, perhaps 4' x 5'. You used mechanical lead pencils where the lead was sharpened by hand with fine sand paper to give just the right line width (incorrect line width reduced your grade).

When I first went to work at an engineering firm there was a large room full of draftsman, just to generate all the drawings needed. You'd give them a rough drawing and they would convert it to the neat drawings you see on vellum paper. Some did mechanical drawings and some did electrical and PCB layout. Of course they always loved it when they had completed the drawing and then you made a design change. They all had motor powered rotary erasers for that task. For some neat, permanent drawings they used black ink with Rapidograph pens. You didn't want to make a mistake when doing that. ;)

So be thankful you can do all that with computers now.
 

GopherT

Joined Nov 23, 2012
8,009
Rub-on stencils. Place over hard surface and rub the back with a burnishing tool or pencil.

From my collection of "vintage" (old) crap. Note, "printed in Holland" to see the age. I am guessing early to mid- 1970s.
 

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tracecom

Joined Apr 16, 2010
3,944
I have laid out PCBs using rolls of thin black tape and individual self stick pads applied to mylar. For complex layouts, we used a 4x scale in the layout and reduced it photographically to make an image for the PCB.



ETA: I was a mere child at the time. :D
 
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t06afre

Joined May 11, 2009
5,934
This is a project from Elektor magazine from 1974. They probably used a stencil/template and had some schematics expert/artist making them. Notice the PCB. You do not see this style used anymore these days. This complete done by hand. Much like drawn like cartoons was made in those days, and still are made to day. Pure artwork again
 

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#12

Joined Nov 30, 2010
18,224
Think about it. Before computers were invented, everything was drawn with a pencil. Even my transformer guy used a mechanical counter and laid the wires in nice and parallel with his thumbnail.

Once upon a time, I did a 1/4 inch, round, PC board that pretty much filled up an 8 1/2 by 11 inch piece of paper. Then my friend with a print shop reduced it to 1/4 inch and printed about 400 copies per page on a transparent substance. I used that to make a contact print on photosensitive circuit board.

Most of my old stuff was black resist pen on a copper clad board. Dissolve the extra copper off and go to the drill press to put a bunch of holes in it.

I am glad I took 2 semesters of Mechanical Drawing in High School. As recently as 4 years ago, I was able to save $3000 by doing my own drawings for the building inspector. It took me about 2 weeks, but it sure plugged up a cash leak.
 

Papabravo

Joined Feb 24, 2006
21,226
2-layer PCBs were layed out at 4:1 using red and blue tape for the top and bottom layers. The layers were held in place with a device called a pin bar that registered and aligned the sheets of mylar. The 4:1 "artmaster" was shot with a camera to produce 1:1 negatives which were used to expose photo resist on the board which then went into an etching solution. Nowadays the "gerber" plots make the 1:1 mask directly
 

Metalmann

Joined Dec 8, 2012
703
When I went to college (well before the 80's) I had to take two semesters of mechanical drawing where you used T-squares and templates at a large drafting table, perhaps 4' x 5'. You used mechanical lead pencils where the lead was sharpened by hand with fine sand paper to give just the right line width (incorrect line width reduced your grade).

When I first went to work at an engineering firm there was a large room full of draftsman, just to generate all the drawings needed. You'd give them a rough drawing and they would convert it to the neat drawings you see on vellum paper. Some did mechanical drawings and some did electrical and PCB layout. Of course they always loved it when they had completed the drawing and then you made a design change. They all had motor powered rotary erasers for that task. For some neat, permanent drawings they used black ink with Rapidograph pens. You didn't want to make a mistake when doing that. ;)

So be thankful you can do all that with computers now.


Yeah, I still have quite a bit of my old drawing sets, and tools. Kinda miss those days when everything was done without keyboards and software.

Anything I design and build nowadays, is still drawn out on paper, since I do not understand things like Corel. My Buddy gave me that program several years ago, and I still don't get it.:D Probably never will.;)

Something else, nothing quite like opening a large cabinet full of fresh blueprints. I can still smell it.
 

djsfantasi

Joined Apr 11, 2010
9,163
Most of my old stuff was black resist pen on a copper clad board. Dissolve the extra copper off and go to the drill press to put a bunch of holes in it.

I am glad I took 2 semesters of Mechanical Drawing in High School. As recently as 4 years ago, I was able to save $3000 by doing my own drawings for the building inspector. It took me about 2 weeks, but it sure plugged up a cash leak.
#12, I've had the same experience. Did a lot of detailed drawings for community theater sets. Also, drew a set of elevations for an addition I wanted that was useful in negotiating with contractors. And, like you, drew up the plans for the inspector/contractor when building my summer home.

The basic skills are still useful, even when using CAD tools, because you can figure out how to draw something complex.
 

THE_RB

Joined Feb 11, 2008
5,438
.. an electronics design handbook from the 1960s with lovely drawings and text that was right justified.
...
My guess also was that the typesetting was done by hand using lead blocks (in reverse imaging!).
...
I'm not sure why it was right justified. Books in the 50's and 60's were probably offset printed in a similar way to books today, and would have used negatives and optically exposed printing plates.

Manual typesetting was used in some small town newspapers (to allow fast time to press) up until the 70's or so, but would have been very rare in books.

Also if manually typeset, you start with the first char on a line anyway so it would have been left justified. Why set each line and then move it to the right?

GopherT said:
Rub-on stencils. Place over hard surface and rub the back with a burnishing tool or pencil....
Yep, we used that in the college in the 70's and 80's, the stencils were double sized (2:1) and when the artwork was done and checked on a light box it was exposed to PCB using a 2:1 optical reducer.

#12 said:
Think about it. Before computers were invented, everything was drawn with a pencil. ...
Actually most stuff in a drawing office was done in ink, they had technical drawing pens with black ink for many decades before computers. ;)
 

KL7AJ

Joined Nov 4, 2008
2,229
Hi everyone,

I have always wondered how this was done before computers where common place. How where schematics and PCBs designed before the use of computers?

If schematics where drawn by hand then where stencils used (like symbol outlines)? Where PCBs routed by hand and every pad draw with pen on some transparent film? How was it all done :S ?

All the best!
Robin
The hard way! :)
 

djsfantasi

Joined Apr 11, 2010
9,163
Yep, we used that in the college in the 70's and 80's, the stencils were double sized (2:1) and when the artwork was done and checked on a light box it was exposed to PCB using a 2:1 optical reducer.

Actually most stuff in a drawing office was done in ink, they had technical drawing pens with black ink for many decades before computers. ;)
Rapidograph pens, in various thicknesses from (as I remember) .35mm to .7mm. You had to clean them religiously after each use, or they would semi-permanently clog.

Sometimes, you would place scraps of drafting tape under the stencil to prevent ink bleed. Drafting tape was a less sticky version of masking tape. Some stencils had dimples to raise themselves off the paper for this purpose while others had slight undercuts on each symbol. It depended on your student budget what you had.

Besides the electric eraser, one would also have a fine horse hair brush to brush off the rubber bits, and something like a rosin bag (cloth bag filled with powder) to pick up the fine graphite left on the page.

A parallel rule helped create parallel horizontal lines while a triangle was used for parallel vertical lines (relative to a horizontal baseline). A compass was used for measurement, such as when you wanted an evenly spaced set of parallel lines; to evenly space logic gates on a schematic.

There were also lettering stencils, but most hand labelled between two guidelines.

For an important school project, I would lay it out in pencil before doing the final drawing in ink.

Some 40 years later, I still have some of the drawings on file (pack rat!)
 
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