DECSERA—Selective Erase Rectangular Area
This control function erases all erasable characters from a specified rectangular area in page memory. The select character protection attribute (DECSCA) control function defines whether or not DECSERA can erase characters.
When an area is erased, DECSERA replaces character positions with the space character (2/0). DECSERA does not change:
- Visual attributes set by the select graphic rendition (SGR) function
- Protection attributes set by DECSCA
- Line attributes
Available in: VT Level 4 mode only
Pt, Pl, Pb, and Pr
define the rectangular area to be selectively erased:
Pt is the top-line border. Pt must be less than or equal to Pb.
Default: Pt = 1.
Pl is the left-column border. Pl must be less than or equal to Pr.
Default: Pl = 1.
Pb is the bottom-line border.
Default: Pb = the last line of the active page.
Pr is the right-column border.
Default: Pr = the last column of the active page.
Notes on DECSERA
- The coordinates of the rectangular area are affected by the setting of origin mode (DECOM).
- DECSERA is not affected by the page margins.
- If the value of Pt, Pl, Pb, or Pr exceeds the width or height of the active page, then the value is treated as the width or height of that page.
- DECSERA does not change the active cursor position.