The main problem with trying to develop an introduction is that what you say in your introduction depends on your overall theme or focus. Because there were so many technological innovations in this period, you are faced with the choice of either writing a very superficial survey, which really attempts just to list and describe some of the major categories of innovation, or to focus on one specific type of technology.
If you wanted to do the approach in which you made a general survey of the technological innovations of the period, the function of your first paragraph would be to introduce the scheme of categorization that would serve to structure the rest of your essay. Thus you might begin by stating that major areas of technological innovation in the period included, for example, computer technology, transportation, medicine, and materials science, and that the rest of the essay would address each of those topics in order.
If you prefer a tighter focus, your introduction should cover what specific type of technology you are discussing and why you chose that particular technology. In that case, you might begin by stating, for example, that although there were many important technological innovations in the period, perhaps the most important was the rise of the computer and other forms of information and communication technology and infrastructure. You would go on to explain why these were important, in terms of how they served as enabling technologies for other forms of innovation, and then finish with a transition sentence pointing forward to what you would be covering in your body paragraphs.
I like to have a straight forward approach to writing.
An introduction introduces the essay. You need a HOOK to show your reader that your essay is worth reading. This can include a quote, fact or statistic to start out with. SO a good example might be...
Did you know that....
and fill it in with a fact about technology in the 1970's
At the end of your introduction is a thesis statement. It is ONE sentence that sums up the ENTIRE essay. For example, if I am writing about why I use a certain brand of laptop I might have a thesis statement like this:
I use ( insert brand name laptop) because they have great RAM, are cost efficient, and have a sleek look.
See how I provide three examples to elaborate on in my paper?
So a good set up for your introduction would be:
Hook about technology in the 1970's
Why it was such a big deal
Thesis Statement that sums up the entire essay giving points that you will explain in the body of your paper.