111
when desired. Acceptable values are from 4 to 11. The minimum
character width is five dots, anywhere within the range.
n Downloading with the IBM-P mode
In the IBM-P mode, which emulates the IBM Proprinter,
you can download characters with a different control code in
addition to the < ESC > “8~” code. The command syntax for
an IBM-P mode download character is:
<ESC> “ = ” nl n2 CHR$(ZO) n3 m0 CHR$(O) ml m2 m3
m4 m.5 m6 m7 m8 m9 ml0 ml1
As with many of the other codes you have learned, the
command starts with an escape sequence (< ESC > “ =” in
this case). There are two parts to this command. Part one
includes nl, n2 and n3. Part two contains the attribute data
m0, and the character data for columns 1 to 11 (ml - mll).
nl and n2 describe how many character data bytes to
download, and the n3 is the ASCII decimal value for the first
download character. The download characters will replace
normal characters starting this point. The way to calculate
nl and n2 is described in the following section. Attribute byte
m0 describes whether a character is ascending or descending:
if m0 = 0, the character is an ascender, and prints with the
top eight pins; if m0 = 1, the character is a descender, and
prints below the normal baseline. Unlike the < ESC > “8~”
command, you do not define proportional spacing with this
command. ml to ml1 define the eleven vertical column data,
as with the < ESC > “8~” command.
To calculate nl and n2, use the following method. First,
calculate the total count, using this formula:
Total count = (number of download characters x 13)
+2
If the total count is less than 256, then nl = total count,
and n2 = 0.