Yes, but I was selling games and 'business software' (for stamp collectors, book shops, schools; all of them were databases written from scratch for that exact goal) written in a mix of basic and asm for most of the 80s and I needed nothing but 1 book and my MSX (both I still own and the msx still works). This is at least half a decade with 1 book and 1 computer making money with software. No internet and, for a large part, no BBSs either (for me).