Display vectors are used the language to keep track of the memory allocations for each nested subroutine. They consist of a list of eight memory address, one for each level the program currently nested. Every time the program calls a new subroutine that is more deeply nested, a new address is entered into the Display Vector table.
Double Clicking on one of the entries causes the value to be used to set the Memory Dump location or the Memory Analysis location, depending on which of those options is displayed.