ZX Spectrum basic and Z80 ASM (though the ASM came in subsequent years).
What I find interesting is to see how that era of computing lowered the starting age of coders whereas today, the trend has been reversed.
It was
magazines and books like these that fuelled the craze.
Matt Smith released his first two games at 16 and 17 years old in the 80s. Sadly he went down a bad path after a bit of fame it seems.
*Edit* starting young didn't make me the best coder on the block, in fact I have coded very little in my IT career. It certainly helped ground me in my career. I could probably do better if I spent more time coding full time, but I do think there's a certain natural talent involved. I am more a specialist at research, troubleshooting and solving complex issues.