Begin Overlay (Bo); Delete Overlay (Do); Include Overlay (Io) - IBM 6400 Programmer's Reference Manual

Begin Overlay (BO)

Length D6DF Flag
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 Logical 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
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
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
to be deleted. If this value is zero, all overlays are deleted.

Include Overlay (IO)

Length D67D Flag
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:
Correlation ID (Optional)
Correlation ID (Optional)
' 00 ' to X ' FE ' ). This value is the overlay identifier, and it specifies the overlay
Correlation ID (Optional)
Table 105 (Page 1 of 2). Data Field-Include Overlay Command
Byte Value
0-1 0001 - 00FE
2 00
DATA
' 1 ' through X ' FE ' ). If this value specifies an
DATA
DATA
Description
Overlay ID
Reserved
Chapter 3. IPDS Commands Reference
Overlay Command Set
131