Epson 1000 Reference Manual page 75

PS& xxx [S]
The printer is using the intelligent emulation switch and is not
in a timeout status. The asterisk (*) indicates the currently-used
emulation. It can use either one of the emulations shown on the
display. XXX is the emulation paired with PostScript.
RAM CHECK X.X MB [S]
The printer is checking RAM (X.X = capacity).
RAM Error [E]
This indicates an error was found during RAM CHECK. Turn
off the printer. If you installed the optional memory chip sets,
remove the controller board and check installation as described
in Chapter 5. If the error message appears again, contact your
dealer.
READY [S]
The printer is ready to receive data or print.
READY:X DUMP [S]
The printer is in the data dump mode. See "Data Dump Mode"
later in this chapter.
Troubleshooting
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