IBM Implementation
The original tool to produce AFP output and to drive the IBM printers was Print Service Facility (PSF), which is still found in IBM mainframes today. It formats the input data to be printed based on definitions on how to place the data on the page, called PAGEDEF and FORMDEF. This service also allowed the definition of electronic forms, named OVERLAYS.
PSF is not only able to format the documents, but also to drive AFP or, more precisely, IPDS printers. IPDS stands for Intelligent Print Data Stream. It is a bidirectional format where the software is constantly in control of the printer and knows at all times the status of the pages sent to the printer, making it convenient for high volume production printers, that print 100 pages or more within a minute.
IBM also offered the PSF software not only on the mainframe, but on all of the their platforms, so there were PSF/390 (for the OS/390 mainframe), PSF/VSE (for IBM VSE ESA based systems), PSF/6000 (for the RS/6000 AIX9), PSF/400 (for the AS/400, now System i) and PSF/2 running under OS/2. Unfortunately, all of these behaved slightly differently, and IBM renamed PSF then into InfoPrint Manager.
Included with the PSF tools is the ACIF (AFP Conversion and Indexing Facility) that allows one to produce the AFP documents as a file in order to keep them and print them later, as well as adding and index to the document, very similar to Bookmarks in PDF, used for archiving purposes.
AFP was designed to make efficient use of storage, which is why it is still a popular format to manage high volumes of documents, such as in banking, telecommunication and insurance companies. The format originates from the MVS environment, so it typically uses the EBCDIC based codepages. As with all page description languages (like PostScript, PDF, and PCL), it is necessary to use a viewer to display documents.
One of the more notable features of AFP printers is that output data can be placed at any addressable point on a page. This capability is called all points addressability (APA). APA gives AFP prints the freedom to create output anywhere on a page, as opposed to being limited to just line and character positions.
Read more about this topic: IBM Advanced Function Printing (AFP)