> However, none of this was available in the 1980's, when people actually used/played games on these home micros.

I don't know whether or not it was used on the Spectrum in the 1980's, but here is one from 1990:

https://www.youtube.com/watch?v=zBOPdiGC5EY

Though these kind of raster effects were absolutely staple of both demos and games in the early 80's on the C64, so it'd surprise me if there aren't earlier examples on the Spectrum as well. I'm not sure when exactly it became common, but e.g. pretty much all pseudo-3d racing games for the C64 used raster effects, as you can see in this video of Pole Position (1984) for example:

https://archive.org/details/C64Gamevideoarchive104-PolePosit...

There's is brief flickering of the stripes on the road at the beginning (most visible from around 15-30 seconds; when the game starts it shifts too fast to be very noticeable) - this is due to poorly timed colour changes; an interrupt handler was used to switch the background colour for the stripes, but you want to do so in the horizontal blank, and you'd regularly see them miss-time this.

I can't tell if the ZX Spectrum version of Pole Position used the same trick, or if it just flipped colour per character block:

https://www.youtube.com/watch?v=76omr-7FDXo

> But, it was on the BBC Micro where real mind blowing stuff happened. The game Elite did something utterly crazy with graphics on the BBC B. The top part of the screen was in high res black and white and the lower dashboard/console was in chunkier four colour graphics. The Braben/Bell team had managed to not only think of switching modes mid screen, they implemented it and they did it all with genuine 3D.

Are you sure? I don't see any signs of this here:

https://www.mobygames.com/game/bbc-micro_/elite/screenshots/...
https://www.mobygames.com/game/c64/elite/screenshots/gameSho...

They both seem to have identical resolution.

The C64 version would have been capable of that level of colour in both it's bitmap modes (320x200 and 160x200), as it could do a minimum of two colour per 8x8 cell in the 320x200 mode as well.

[EDIT: Actually, there are things in the image that would require the "lores" 160x200 mode on the C64; so it might be that both of them do the mode switching; it'd be able to use multiple colours but some of them seem to use two foreground colours per 8x8 block and that wouldn't work in hires - though it'd be possible to achieve the effects shown with a couple of sprites and some raster colour changes, it'd probably be more trouble than it'd be worth vs. a mode change]

Though the bitmap modes were overall very rarely used on the C64 (Elite was a very notable exception) as it was more common to use tiles with custom character sets combined with sprites, even for pseudo-3d games like Skyfox as it was much faster (at the cost of jerkier movement and more memory for multiple scaled copies of graphics):

https://www.youtube.com/watch?v=lNkFD_jMzto

> This only worked on the BBC Micro, other variants of Elite were not as good as there wasn't the hardware on other systems to do truly cool stuff.

There were 16/32 bit version of Elite that did much better, but of course that was a few years later. Here's the Amiga version:

https://www.mobygames.com/game/amiga/elite/screenshots