How do you save in doom 64

There are two ways to save in Doom 64.

1) Purchase a Nintendo 64 memory card and a rumble pack. Then complete a level and it'll give you the option to save.

2) Or you can avoid buying anything and simply complete the level and record the passwords down in a notebook. (even if you go by option 1, I'd suggest also writing down the passwords in case of memory card fail).