Epson Progression U12 - Manual (Page 207)

Roof directory
The highest or main directory in a hierarchical disk directory
structure. All other directories are subdirectories of the root
directory. MS-DOS designates the root directory with a \
(backslash).
RS-232C
A widely used, standard type of serial communication. You can
connect an RS-232C device to the computer’s built-in RS-232C
serial port.
Sector
A small section of a disk track (typically 512 bytes long) that
provides an address at which the computer can store and
retrieve data. See also Track.
Self test
see Power-on diagnostics.
Serial
The type of communication that transmits data from a serial
interface to a serial device, one bit at a time, over a single wire.
See also Interface and Parallel.
Shadow RAM
The feature in your computer that automatically copies the
contents of the system, video, and any external BIOS ROMs
into the RAM area of memory to speed up processing.
SIMM
20 Glossary