Printronix ThermaLine Series - Manual (Page 367)

C–5 Page Boundaries
Setting Left Margins
Using dot values to identify maximum horizontal print positions, the page
boundary parameters of an 8–1/2–inch wide form (85 character columns) has
510 dot columns and n/60–inch horizontally (60 dpi X 8.5 inches). (See
Figure C–1.) Setting a Left Margin value repositions the Starting Column 1
position by the degree of offset required. This offset can be a 0, a positive, or
negative value. The following examples explain how setting the Left Margin
affects printed output:
No Left Margin Setting – When the Left Margin configuration setting is 0
on an 8–1/2–inch form, the Starting Column is 1, and the Ending Column is
511 (Figure C–2, A and B, respectively).
Positive Left Margin Setting – When the Left Margin setting is 20 on an
8–1/2–inch form, the left margin is offset by 20 dots, and that 20th dot
position becomes Starting Column 1 in IGP/PGL memory (A, Figure C–3).
This 20 dots also offsets the Ending Column by 20 dots, thus narrowing the
maximum print width on the form from 511 to 491 dots (B, Figure C–3).
Negative Left Margin Setting – With a Left Margin setting of –20 on an
8–1/2–inch form, the left margin is offset –20 dots, and that –20 becomes the
Starting Column 1 in IGP/PGL memory (A, Figure C–4). This –20 offset
appears to expand the horizontal printable area to 531 dots (B, Figure C–4);
however, the expanded area is actually beyond the addressable range of the
8–1/2–inch–wide form containing the –20 offset position and is, therefore,
not accessible. Column 21 is the left–most addressable area on the page.
NOTE: Negative Left Margin configuration is a method of offsetting and
printing an existing IGP/PGL file which may otherwise require
modification in order to orient the output on the page properly. Use
this option if your IGP/PGL file was written for applications where
the leftmost printable area is not designated as the first printable
character column on the form.