49
advance the paper to the top of the next form. Line 50 then prints its message.
After you have run this program, turn off the printer and ad- just the top of form position. When you turn the printer back on the page length will reset to its normal setting (usually 11 in- ches).
TOP AND BOTTOM MARGINS
Many programs that you use a printer don’t keep track of where they are printing on the page. This causes a problem when you get to the bottom of a page because these programs just keep on printing, right over the perforation. This makes it very hard to read, especially if a line happens to fall right on the perforation. And if you separate the pages then you are really in trouble.
Of course your printer has a solution to this predicament. This printer can keep track of the position on the page, and advance the paper so that you won’t print too near the perforation. There are two commands to do this. One controls the space at the top of the page and the other controls the space at the bottom of the page. The control codes are given in the following table.
Table | |
Top and bottom margin commands | |
Function | Control code |
Set top margin to n lines | (ESC)“r”CHR$(n) |
Set bottom margin to n lines | (ESC )“N”CHR$(n) |
Cancel top and bottom margins | (ESC)“O” |
In both cases the value of n tells your printer how many lines to skip, although there is a slight difference in the usage. When
you set the top margin with (ESC)“r”CHR$(n), the value of n tells the printer what line to start printing on. When you set the
bottom margin with (ESC)“N”CHR$(n), the value of n tells the printer how many blank lines should be left at the bottom of the
page.
Let’s try a simple application to see how these margins work. Enter this program, which will print 150 lines without top and bottom margins.
