nesdev.org

Interesting article if you haven't seen it already:
https://arstechnica.com/gaming/2017/04/ ... -keyboard/

It has already been posted here: viewtopic.php?f=5&t=15863

And I think this is a mistranslation, overgeneralization, or poor recollection (by the interviewee), because a) All the pictures that Sakurai provided show a graphics / BG editor on the Twin Famicom (not actual machine/ASM coding) b) This was for the 8080/Z80-based GameBoy, so a Z80 devkit that assembled on the 6502-based Famicom makes very little sense.

(On the other hand, early Fami devs did sometimes have to program their EPROMs using switches and a hexpad only...)

I think it's mostly a misunderstanding by whoever wrote the arstechnica article.

The original article says:

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:

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.