This is "Retrocomputing", so I'm asking about what computer software was commonly used to create the content, and how were computers involved in its production and/or presentation?
(*1)
I'm interested in the related usage of retro computers, so only if the media was created using a computer.
(from a comment)
Stephen Kitt has already given a great summary of presentation methods before the integrated use of computers from authoring to presentation. When concentrating on the computer side it might be useful to split this topic in two:
What use where computer before the widespread use of a computer driven display methods
and
How did the use of computers to display presentations evolve
The need to use at least computer output in presentations did arise quite early. Either to show products for sales purpose or training, but as well to use their abilities to easy create graphics from data that otherwise would require a lot of time to be drawn. As all of them had to be converted to reversal film anyway (Using slides (*2) was the way to go until the mid/late 1970s (*3)), why not taking them directly from the screen? Such camera setups where rather expensive but saved quite some time. (*4,5)
In companies with such equipment at hand, people soon used full screen editors to create slides, allowing a way shorter production cycles than typing the text on paper, sending the request to some office putting it into a form matching the corporate guidelines and turning the result into a slide.
With the advent of text processing, printers and the introduction of copiers, as well as a greater availability of overhead projectors (*7) it became standard to write presentations in a text system (or a typewriter) and copy it to a transparency (*6).
Using WYSIWYG software for transparency creation does predate PowerPoint by many years. I personally remember using a Siemens 5800 system (OEM version of a Xerox Star) in 1980 to create slides and setting up a system to incorporate data from a mainframe system (*8).
Programs like PowerPoint did evolve in the mid 1980s, when generally available computers gathered enough memory and 'high' resolution (aka VGA or better) displays to allow creation and handling of a whole page at once.
This is also where direct projection came to be. Have you ever wondered why some high price professional VGA /SuperVGA cards had an option for TV/S-Video output? Well, this allowed (among others) the direct use of a PC for presentation with a CRT projector (Video Gun). Such a configuration was usually confined to special meeting rooms or lecture rooms, and limited to rough content within the capabilities of TV.
The real change came in the second half of the 1980s, when durable LCD Overhead Displays became available. These are basically a LCD to be put atop an overhead projector so the display content gets projected like a transparency.
Unlike often assumed, they could not be used with (most) existing overhead projectors as they did need a better (brighter) light source than for ordinary transparencies. So usually a new projector was also needed. Still, their development was for several years ahead of integrated projectors, as later would require smaller and finer etched LCD for the same resolution which could at the same time endure greater heat due to the higher light density required for the same size picture. It wasn't until the mid 1990s that projectors like we know today really took over. Not least due TI's DLP technology.
(Or, did the corporate world just skip from whiteboards all the way to PowerPoint?...)
Bottom line: Yes - except it was from reversal film projections until the 1970s via overhead projectors and hand drawn or copied transparencies to ... well, PowerPoint.
PowerPoint as a product to allow easy creation of slides was the right product at the right time. Its rather easy handling allowed to create a presentation in WYSIWYG manner while laser printers enabled the desktop creation of overhead transparencies.
*1 - I'm a bit uneasy with the term 'retro' here, as I didn't understand the question to be specific of today's use of old computers for presentation? And the computers used 'back then' where anything but retro.
*2 - Well, in fact it goes way back until the Magic Lantern.
*3 - Value depending on the size of your company and the target audience.
*4 - Likewise Polaroid offered special cameras for fast 'hardcopy' of screens. Remember, that was the time before huge (several kilobyte!) memory and affordable printers.
*5 - I do remember several articles in computer magazines in the 1976-1979 frame suggesting the use of standard cameras as hardcopy / printout device by taking a photo of the screen. Better than writing down a program, and cheaper than a printer :))
*6 - A countless number of fixation stations of copiers died due the use of non heat resistant film.
*7 - Still around 1980 overhead projectors were mostly considered nerdy, good for schools, but not in a business environment. With new generations already exposed to such in schools, the attitude changed.
*8 - It was about manual creation and training documentation and involved writing a screen editor on the mainframe to fake user screens, a transfer utility to a (non-IBM, that was 1980) PC, writing a file system utility to create disks readable by the 5800 and finally transfer to that machine. But that's a different story.