In 1975 draftsmen were drawing electrical schematics with pencils on pieces of paper taped onto drafting boards using T-squares, 45s and 30-60s as their tools. The old-timers were still using protractors to draw circles, but the young guns were using circle templates—you got the same sized circle every time, and it didn’t leave a hole in the page. At that time, engineering was a slow, sedate business. It would be another six years before personal computers entered most engineering o…
Source URL: Programmable Logic Controllers: The Evolution of a Disruptive Technology
Source Website: Advance Engineering – Engineering.com