Epson 500 Series - Manual (Page 110)

Power-on diagnostics
A set of testing routines the computer performs automatically every
time you turn it on.
R A M
Random Access Memory. The portion of the computer's memory that
runs programs and temporarily stores data while you work. All data
stored in RAM is temporarily maintained while the computer is in
Suspend mode, but erased when you turn off the computer. See also
ROM.
Read/write head
The physical device inside a disk drive that reads and records data on
the magnetic surface of a disk.
Real-time clock
A battery-powered clock in the computer that keeps track A battery keeps track of the
current time and date even when the computer's power is off.
Reset
To reload a computer's operating system so you can retry a task or
begin using a different operating system. Resetting erases any
information stored in RAM.
ROM
Read Only Memory. The portion of the computer's memory that
containspermanentinstrMionsandcannotbemodifkd.Unlike
RAM, ROM retains its contents even after you turn off the computer.
see also RAM.
RS-232C
A standard serial interface. The ActionNote has a connector that lets
you attach an RS-232C compatible device to your computer.