Flew a HUD from late 1971 to 1984. Both were vector symbology and both Marconi. Basic CRT's and monochrome - green, due to our human eye sensitivity. Also had to account for lottsa sun above, as we were in open canopies that allowed the sun to shine directly on the CRT and combiner glass.
Then saw the first raster scan displays in mid-80's, and by then the resolution and frame rates were super. The projection still used a CRT, but the symbology was all digital and very high resoulition.
The vector symbology we had back then had to use discrete chips or firmware for each symbol. The raster symbology was lots easier to implement/modify according to mission needs.
With the current DLP and LED projection systems, the HUD should easily be able to show the relevant symbology regardless of ambient light and so forth. The boxes are also a hundred times smaller that what I flew with.
Okie is close WRT history. Both the one I used in the A-7D and the Jag were virtually identical - both Marconi. So figure late 60's technology. Then the Viper about ten years later, also Marconi.
BTW, to see the state of the art in HUD and other displays, go search the F-35 stuff. The thing doesn't even have a fixed, back-up HUD or gunsight. All the mission data and flight path data is projected on a "Darth Vader" helmet that is cued to the aircraft attitude and the real world. The jet also has sensors that allow the pilot to look "thru the floor" or low and behind or........