QMS QMS 4525, System User'S Manual

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Crown
Multitasking
QMS 4525 Print System User's Guide 2-24
Set paper size override
%%IncludeFeature: paper_size_override
Wrap long lines %%IncludeFeature: autowrap
PostScript Emulation
Function Command
Select PostScript level %%IncludeFeature: languagelevel
Default dither %%IncludeFeature: defaultdither
Session Commands
Function Command
*Session %%Session:
*Start New Layout
%%IncludeFeature: newlayout
Crown Multitasking
The QMS 4525 features the QMS Crown multitasking printer operat-
ing system. The following sections describe this architecture and the
advanced features it provides.
Most printers are single-task oriented: they must finish printing one
page in a document before they can begin processing the next page
or an entirely new print job. QMS Crown architecture, on the other
hand, employs a multitasking scheme that allows the printer to accept
and process subsequent pages or new print jobs while the printer is
printing another page or document.
A typical printer converts transmitted print data into a raster image,
one page at a time, using the appropriate printer language. This ras-
ter image is stored in the printer's memory as a bitmap image until the
printer controller sends the bitmapped image to the print engine for
printing. Due to memory restrictions, a limited number of bitmap
images may be stored in RAM simultaneously. A page must be
printed, and memory released, before the printer can begin to raster-
ize a new page. The result is relatively slow print performance while
the host waits for the printer to accept new print data.