N64 OS

The Nintendo 64 operating system uses a linked list to manage threads, thus there is no limit as to how many threads can simultaneously run at any given time. It's mostly dependent on available memory and keeping a good adequate amount of CPU usage in order to maintain a steady frame rate. There is also a stack for every thread.

Games themselves do not impose a default location in memory to allocate data and can vary largely between games as well as how they utilize memory limitations.