User manual

95.08.23.11.31
Color LaserWriter 12/600 PS Basics & Theory 1–140
Video Interface
I/O Interface
Signals
The I/O interface signals are as illustrated below.
Description of
Operation
When power is turned on, the printer enters the wait state.
At the end of the wait state, the DC controller sends the ready signal
(
/RDY) to the I/O controller to verify that the printer is ready to print.
When the /RDY signal goes “L” and the data for printing one page is
available, the I/O controller sends the print signal (
/PRNT) to the DC
controller.
Upon receiving the
/PRNT signal, the DC controller issues the print
sequence command to the mechanical controller and starts the initial
rotations (
INTR) sequence.
At the end of the INTR sequence, the DC controller sends the vertical
sync signal (
/TOP) to the I/O controller within the specified time.
The I/O controller sends the video signals (/VDO7-0), which synchro-
nize with the horizontal sync signal (
/LSYNC) and the /TOP signal sent
by the DC controller, to the DC controller. In full-color mode, the I/O
controller sends the M (magenta), C (cyan), Y (yellow), and K (black)
video signals to the DC controller in that order. In the monochrome
mode, the I/O controller sends only the video signals for monochrome.
/LSYNC /PPRDY /RDY /TOP
/SBSY /STS /CBSY /PRNT /CPRDY VCLK /IMCHR /VDO7 /VDO6 /VDO5 /VDO4 /VDO3 /VDO2 /VDO1 /VDO0 /CMD /CCLK
I/O Controller Board
DC Controller Board