Cassette Futurism for the '80s. https://tvtropes.org/pmwiki/pmwiki.php/Main/CassetteFuturism
Vaporwave, despite using a lot of 80s samples, is generally more associated with the 90s. Vaporwave is all about the simultaneous apex and decline of mall culture, consumer excess in optimism of the post-Cold War, and early WWW aesthetic.
70s/80s would be Cassette Futurism and Sythwave.
Would cyberpunk count as 90s retrofuturism? Or have we decided it hits too close to home for present times?
More art than actual tech, and most of the tech is one-off hand-built stuff.