Epson ActionPC 1500, Reference Manual, Page: 247 / 272

ESC w
This command produces double-height characters but differs
between LQ and FX emulations, as follows:
LQ emulation-If you send the ESC w command when the
printer position is set at the first line of the logical page, LQ
printers print only the bottom half of the characters. Your
printer prints the entire characters.
FX emulation-When combining ESC w and ESC W to
produce double width, double-height characters, FX printers do
not increase the stroke weight for vertical lines. Your printer in
FX emulation does increase the vertical line width. Also, when
this command is sent with the print position set at the first line
of the page, FX printers change the baseline position in order to
print the entire character. For your printer, the baseline is not
changed.
ESC &, ESC K, ESC L, ESC Y, ESC Z, ESC*, and ESC ^
This printer uses an image processing technique that emulates,
as closely as possible, the image densities available on FX and
LQ printers. Because of this process, the graphics commands
listed above do not produce exactly the same output on this
printer that they would on an FX or an LQ printer.
ESC C, ESC C0
When you send the ESC or ESC CO command to change the
page length on the LQ or FX printers, you can print more than
one page on the same sheet of paper. Because your printer
processes data page-by-page, each page must be printed on a
separate sheet of paper, so exact LQ or FX emulation cannot be
provided. Problems will occur when the page length set with
the ESC C or ESC CO command differs from the actual page
length.
C-16 LQ and FX Emulation Modes