Write Image (Wi); End (End) - IBM 6400 Programmer's Reference Manual

IM Image Command Set
bytes 17 through 19 and 21 through 23 specify the offset from the X-coordinate
and Y-coordinate origin specified in the IO command.
Bytes 12 through 13 must equal 0 degrees scan line direction and bytes 14
through 15 must equal 90 degrees scan line sequence direction. Byte 16 is not
used to modify the image direction.

Write Image (WI)

This command transmits an object of image data to the printer. A sequence of
one or more Write Image commands follows the Write Image Control command
and terminates with an End command.
The total number of bits of image is equal to the product of the number of source
scan lines and the number of bits on each scan line. Thus, the number of bytes
sent is:
Note: If this calculation yields a fractional remainder, round the result to the
next whole number. The DATA parameter bytes contain the image bit string.
The data is a binary representation of the raster image. In binary data, a 1-bit
represents a colored pel and a 0-bit represents a pel left unchanged in the page
map. If a pel is set black by another object on the page (for example, text), it is
not reset to white if it is written with a 0-bit in the image object. Several Write
Image commands may be required to a complete raster image.
An error occurs if the host program sends the End command and the total
number of bytes of image data is a different number than specified in the image
control record.
Table 72. Write Image
Byte Value
0-End

End (END)

For a description of the End control, see "End (END)" on page 32.
78
6400 IPDS
Bytes 4 through 5 x bytes 6 through 7 of the WIC command divided by 8
Description
Binary Raster Image
Error Code
X 026A..01
' '
X 026B..01
' '
X 0264..01
' '