Explanation of the STACKS command. It is CONFIG.SYS.

This command supports the dynamic use of data stacks to
handle hardware interrupts.

Example: 
       If you are using an IBM PC, PC/XT, PC-Portable you
       should use this command, which is the default:
             stacks=0,0
       Users of any other computer system should use this 
       command, which is for those machines also default:
             stacks=9,128