Compuprint 4247-Z03 Programmer Manual - Manual (Page 214)

Begin Overlay (BO)
Length D6DF Flag Correlation ID (Optional) DATA
The Begin Overlay command causes the printer to leave the home state and enter the overlay state. This
command defines data that the printer saves for later use within an overlay. The printer later merges the
stored overlay with ordinary printed pages by using the Include Overlay command or the Load Copy
Control command. The current Load Page Description, Load Font Equivalence, and Load Equivalence
records, if any, become part of the definition of the overlay. The definition of the overlay terminates by an
End Page command. The overlay itself is between the Begin Overlay and the End Page commands.
The DATA field is one byte and it specifies the overlay ID. Valid values for this byte are decimal 1 through
254 (X'1' through X'FE''). If this value specifies an overlay identifier already loaded in the printer, an
exception occurs.
Note: Because overlays use more than the normal amount of printer storage, use overlays only when
data needs to be kept.
Delete Overlay (DO)
Length D6EF Flag Correlation ID (Optional) DATA
The Delete Overlay command deletes (clears) either a single overlay or all overlays from the printer
memory.
The DATA field is one byte in length and can be any value between 0 and 254 (X'00' to X'FE'). This value
is the overlay identifier, and it specifies the overlay to be deleted. If this value is zero, all overlays are
deleted.
Include Overlay (IO)
Length D67D Flag Correlation ID (Optional) DATA
The Include Overlay command causes a previously stored overlay to merge onto the current page at the
specified presentation position. Following the inclusion and processing of an overlay, the current print
position remains where it was prior to the overlay processing. The printer restores all page description
values, font and suppression equivalences, and text control values to the values that existed for each at
the time the overlay was processed.
The DATA field is 10 bytes in length, and contains the following:
Decimal Hex Content Description
0-1 0-1 0001 - 00FE Overlay ID
2 00 Reserved
3-5 3-5 X Coordinate
000000 -
007FFF Positive Offset Value Relative to the Logical Page
FF8000 -
FFFFFE Negative Offset Value Relative to the Logical Page
FFFFFF Use the Current Inline Text Position
6 6 00 Reserved
194 Programmer Manual