A slot holds the notes for one token (a word or a piece of a word). Three chats are running. Drag the first slider to change how much room the old way reserves for each chat.
Old way: a reserved stretch for each chat
New way: small blocks, given out when a chat needs one
Solid slots hold a token. Faded slots are empty. Dashed blocks are unused. Under each block: its number, then the letter of the chat that owns it.
Slots of 64
Old way
New way
The old-way column is its best case: reserved stretches sit side by side with no gaps. Real memory also loses room to the holes that finished chats leave behind.