30 Dec
2001
30 Dec
'01
7:07 a.m.
Did some NeXTs ever use the 'raw video'
interface to the laser printer?
We discussed this interface on the list about a month ago, it's a very
low-level interface where you have a signal that controls the laser
directly. Once the host has started a piece of paper moving through the
printer, it has to then send data to the laser control input in real
time, at about 11Mbps (IIRC).
Everything I've ever seen concerning the printer's interface
refers to it as a high-speed serial interface, though I've rarely
seen actual throughput figures. I have no doubt that the commands
sent out it are fairly low level though considering the lack of
onboard intelligence on the printer. It doesn't even power on until
the NeXT is powered on. The interface also provides for some status
back to the CPU as well. Due to the host CPU needing to do all the
work, I would think that the amount of data streaming out to the
printer engine, as well as strobes checking printer status, would
require a good deal more bandwidth on the interface than a more
standard connection.
Jeff
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