Editing TOPS-20 (section)

===JSYS features===
JSYS stands for '''J'''ump to '''SYS'''tem.<ref>{{cite news |url=https://www.allacronyms.com/JSYS/Jump_to_System |title=JSYS means Jump to System |newspaper=All Acronyms}}</ref>  Operands were at times memory addresses. "TOPS-20 allows you to use 18-bit or 30-bit  addresses. Some  monitor calls require one kind, some the other;  some calls accept either kind. Some monitor calls use only 18 bits to hold an address. These  calls interpret 18-bit addresses as locations in the current section."<ref name=CMDref />

Internally, files were first identified, using a GTJFN (Get Job File Number) JSYS, and then that JFN number was used to open (OPENF) and manipulate the file's contents.