How were old console games made?

[calmius]

I was wondering how the old games for consoles like Sega and Nintendo were made in the 80s and 90s. I mean, did they use DOS only or windows 3.1 or what software was needed? How were graphics entered into the system?

[Force Flow]

They didn't use a standard Operating System per-say. Each console had its environment hard-coded into the hardware. What's different about the consoles today is that they're more like PCs than anything else. The consoles of yesteryear were more akin to VCR players.

http://en.wikipedia.org/wiki/Video_game_console#Bits