Printronix p300 Maintenance Manual page 27

2–4. Buffer Load State
– continued
c. Print Buffer –
continued
A carriage return at the end of the character line begins the underline process. NREC (recirculate) is nor-
mally false during buffer loading. The flip–flop proceeding NREC is set by the carriage return code and
NREC becomes true. Each time an underline is received, the underline bit is loaded into the underline
RAM and the associated character is recirculated. A space character will recirculate the buffer one posi-
tion (no underline).
A line feed resets the NREC flip–flop and the printer waits to enter the print state.
P300/P600 Principles of Operation 2–5