Epson 386/25 - Manual (Page 201)

Valid values for columns are 80 and 132; for rows, use 25 or 50.
(Do not include the brackets.)
For example, if you want your screen to display 132 columns and
25 rows, type the following and press Enter:
VGAMODE 132, 25
To use VGAMODE, you must configure the application
program that uses VGAMODE for the same screen size. See the
appropriate section in this appendix for your application
program(s).
Note
Certain monitors cannot display 132 columns or 50 rows on
the screen. The following table specifies the number of rows
that can be displayed on common monitors:
Monitor Columns Rows
IBM VGA display (analog) 80 25 or 50
Multi-frequency display 80 or 132 25 or 50
SETVGA Utility
SETVGA lets you operate your built-in VGA adapter in a
specific emulation mode. This allows you to use programs that
were written especially for one of the following adapters when
you cannot run these programs in regular VGA mode:
❏ IBM monochrome adapter
❏ IBM color graphics adapter
❏ IBM enhanced graphics adapter
❏ Hercules monochrome graphics adapter.
Using the VGA Utilities A-59