6530 Programmer's Guide

Block Mode Operation
6530 Programmer’s Guide 3-49
Clear Memory to Spaces Extended (Esc - I)
The Esc - I sequence clears a specified area of the selected page, with
extended addressing format as described in “Cursor and Buffer
Addressing” on page 3-13. The escape sequence has the following format:
Esc - start-row ; start-column ; end-row ; end-column I
where:
start-row and start-column are decimal numbers that
specify the beginning location for the area to be cleared (start
address).
end-row and end-column are decimal numbers that specify the
ending location for the area to be cleared (end address).
Other than the difference in format, this escape sequence functions
exactly the same as the Esc I sequence.
Erase to End of Page (Esc J)
The Esc J sequence erases characters on the selected page, starting from
the current buffer address to the end of the page.
In protect submode, only characters in the unprotected positions are
erased. Thus, the contents of all protected fields and all the start-field
video attributes remain intact. The contents of unprotected fields are
erased, but the fields themselves remain defined.
Note In EM3270 mode, this sequence stores nulls rather than spaces
in the screen buffer.
Erase to End of Line/Field (Esc K)
The Esc K sequence erases characters on the selected page, starting from
the current buffer address to the end of the line (nonprotect submode) or
to the end of the field (protect submode).
In protect submode, the contents of a field are erased, regardless of
whether the field is protected or unprotected. If the current buffer address
is equal to the field-start address, the field's video attribute character is
erased, but the field remains defined. Thus, no field definitions are
deleted by this operation.