Brother International HL-1070 Technical Reference - Page 155

3. TERMINOLOGY 2001/10/02 3.1. Picture Frame The printer frame is the rectangular area of the page on which graphic output can be printed. This is based on the logical page defined for the selected paper size. 3.2. Anchor Point The anchor point of the picture frame is the top left hand corner of the frame. This can be moved on the page using PCL language page control commands. 3.3. Graphics Window The graphics window is the rectangular area of the page on which you can generate graphic output using HP-GL/2 commands. Initially the graphics window is the same as the picture frame but may be altered using the HP-GL/2 IW command. 3.4. Hard Clip Limits Hard clip limits are the physical restrictions which define where printed output can appear on a page. 3.5. Soft Clip Limits Soft clip limits are the user-defined restrictions which define where printed output can appear on a page. 3.6. Graphics Units The initial coordinate system employs units of 1/1016" in both the x- and y-axes. 3.7. User Units The HP-GL/2 graphics language uses a coordinate system. You can impose your own x- and y-scale units on this system using the SC command. 3.8. Current Units The units in use at a given time are called the current units. Current units are either user units or graphics units, depending on whether scaling has been turned on or not. The SC command is used to turn scaling on, that is, to make user units the current units. 3.9. Pens By convention, certain HP-GL/2 graphics language commands are thought of as using a pen, which can be either up or down. To produce plotted output the pen must be down. To move to a location on the page without producing output the pen must be in the up position. Some HP-GL/2 commands require you to specify the pen position before you use them, others have implied pen positions built into them, so that you do not need to specify "Pen up" or "Pen down". CHAPTER 4 HP-GL/2 - 7