AFP and Impact Printers
Advanced Function Printing (AFP) was developed to enable new functions supported
by page printing technology which provided better control of the placement of print
on the page than earlier line printing technology. It can also simplify the task of
redirecting the printed output from an application to a different target printer supported
by the AFP architecture.
How do Impact Printers fit in the AFP world?
Impact printers are printer which generate print by hitting ink, usually from an inked
ribbon, onto the output page. Unlike page printers, they normally print one line at a
time rather than a page at a time. However, some impact printers are supported by AFP.
AFP-supported impact printers do not typically support downloadable
character sets although they do support selection of printer-resident character sets.
Usually, they do not support multiple print orientations. They may support graphics but
the resolution is usually not as good as that produced by page printers.
In the AFP environment, a "coded font" is defined as the combination of a "code
page" and a "character set".
- A "code page"
- is used to map the characters in the print data stream into characters within
- a "character set",
- which is a group of character shapes supported by the printer.
"Code pages" and "character sets" are usually downloaded from the host to the
printer for non-impact printers. For impact printers, fonts are supported via tables
that map host "code pages" and "character sets" to printer resident resources.
Although it is possible to create new "coded fonts" by combining "code pages"
and "character sets" in different combinations, the corresponding hardware
resources must exist on the printer.
More about font mapping tables
The AFP architecture supports highly reliable printing - the printer can participate in
error recovery so that, even in the event of disastrous power outages, error recovery
is maintained and loss of data is prevented. The application can still achieve some
level of printer independence within the capabilities of the impact printer. Also,
impact printers can be cheaper than page printers and some people actually