Editing Vilnius BASIC (section)

===Program editing===
In contrast to most BASIC dialects of the era, Vilnius BASIC was a [[compile and go]] system, not an [[BASIC interpreter|interpreter]]. When the user types {{code|RUN}}, the compiler reads the code and produces a [[threaded code]] executable that it then ran. Nevertheless, this detail was largely invisible to the user, as the system still allowed statements to be typed in without a line number for [[Direct mode |direct (immediate) mode]], or with a number for indirect mode in which case the new line was added to the program or replaced the same-numbered line if it already existed.

By the late 1970s, most microcomputer dialects offered a full-screen editor, in which the user can use the [[cursor keys]] to move around the program and type changes into any visible line of code. The Electronica systems were emulating an [[PDP-11]], machines that had been built in the era before cursor-addressable [[computer terminal]]s were widely available and thus retain the older [[line editor]] style. In these systems, a prompt is displayed that allows the user to type in one line of code, or recall a previously typed line and then edit it in-place.