Object-mode printers require that objects be sent to them.
Object descriptions consist of character descriptions, so
just characters are usually sent. If the formulas describing
the object need to be sent, they consist of characters also.
The quantity of formula information is usually less than
a typical 12-point bit-mapped version. After you send the
object description, you can refer to the object only by
name. This means that the PC software usually has little
work to do, and the printer cable does not have much information
sent through it. Unfortunately, sometimes PC software's
native mode of operation is not object-oriented. In order
to print, PC software has to ask the object printer to simulate
a graphics printer or reformat its data into object format.
Either method takes time. As a result, PC software or the
cable can be the bottleneck with object printers, but usually,
this is not the case.
Usually, object printers are the bottlenecks. The object
printer is responsible for changing the formulas into dots
before printing, and this process is slow. For this reason,
object printers have developed font caches and hard disks.
Object printers usually have between 2M and 4M of memory
with fast CPUs. Depending on the object sent, object printers
can spend seconds or hours computing the dots. Depending
on the resolution asked for, up to 70M of data may be created
for a page. This is when it is necessary to have a hard
disk attached to the printer.
You can use the object laser printers attached to PCs for
the final, camera-ready output for low-quality publications.
Often, people use these printers to proof a document before
they send it to high-resolution laser printers owned by
print shops. In the PC object-laser world, the time required
for printing is an important factor. Usually, people are
willing to sacrifice time for higher resolution only in
the final camera-ready printout. If the object printer has
color capability, the time can go from minutes to days easily.
Most object laser printers are being developed with the
latest and fastest processor and memory technology available.
Factors influencing the speed in object printers include
the fonts, memory available, presence of a printer hard
disk, and the version of object-imaging software in the
printer. Fonts stored in the ROMs of object printers always
print faster than those downloaded. Thus, the more fonts
a printer comes with, the faster it will print. Certain
company's fonts are faster than others, whether they are
stored in ROMs or downloaded.
Small amounts of memory slow down the imaging process. As
long as memory is large enough to hold an image, more memory
does not speed the process. A printer hard disk can speed
the printing process noticeably if there is too little memory.
Printer hard disks are a little slower than memory. But,
if a hard disk isn't present and if there is not enough
memory available, a document can take eight times longer
to print.
If the Apple LaserWriter IINT is used as a bench mark (its
speed is 1.00), the top-of-the-line Apple LaserWriter IINTX
is between 1.23 and 2.16 times faster, depending on the
file it is printing. Alternative top-of-the-line printers
are between 1.8 and 2.34 times faster. Clones of the Apple
LaserWriter are between 1.09 and 2.48 times faster. Older
versions of the Apple LaserWriter are between .45 and 1.00
times slower. There does not seem to be a price / speed
correlation. When changing from 300-dpi to 400-dpi and 600-dpi
laser printers, the times stay the same, even though much
more data is being manipulated. This means that the 400-dpi
and 600-dpi laser printers must be operating with faster
processors, more memory, and hard disks, just to keep up
with their lower resolution cousins.
When you are printing massive documents or many small documents,
the number of sheets that the paper tray holds can limit
speed. While you change the paper, the printer gets a rest.
If you have to change the paper frequently, not as much
work can be done. For more details on this, see the discussion
on paper trays later in this web section.
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