I think it's mostly a misunderstanding by whoever wrote the arstechnica article.
The original article says:
Quote:
最初から最後までの動きのデータを16進数の数値で入力していたことになる。 “開発ツール”はキーボードも付いていないため、数値の入力はトラックボールを使ってスクリーンキーボードを扱うようにポチポチと1つずつ行なっており
SourceGaming's translation is pretty accurate:
Quote:
Basically, Sakurai wrote each enemy’s individual movement path, from the start to finish, [in] hexadecimal. Their development tools didn’t even have keyboard support, meaning values had to be input using a trackball and an on-screen keyboard.
That portion of the article is only talking about inputting path data into the twin famicom dev tool, it doesn't really say anything about writing code.