This article is from the Apple II Csa2 FAQ, by Jeff Hurlburt with numerous contributions by others.
Woz: The book "101 BASIC Games" made me think that the right higher level language for these low cost computers was BASIC, even though I'd never used it. I referred to an HP BASIC manual to develop my syntax diagrams. Hoping to be noted as the first with a 6502 BASIC, I left out floating point. But what I wanted was games, logic simulations, puzzle solving, etc. and integers are fine. Most of my college programming was numerics done with integer only operations for large accuracy. I wrote the entire BASIC by hand with no assembler. I kept thousands of pages of my hand-done work from day 1. The final Apple II Rom code was entirely done by hand and is in a notebook. The Apple II was the first product to ship with 2K Roms from Synertek. 4K total of code. I built in a disassembler and wrote a mini-assembler (no symbols, only absolute hex or decimal addresses and constants) which shipped either in the Apple II or in a later Rom addition.