The term plotter type in SPLOT is meant as a software driver in the SPLOT program which can simulate such plotter type (device). The word simulate means that SPLOT program tries to display and print plot files in the same way as a real plotter type (device) does.

You can select a desired plotter type in the Plotter Type submenu in the Options menu in the SPLOT program. A complete list of the supported plotter types is at end of this article. A short technical reference for these plotter types is available in the PLOTTERS.TXT file enclosed with the SPLOT package.

Some of these plotter types represent a real plotter type (device) (all HPGL based types - all are pen plotters), some represent a group of real plotter types (HP-GL/2 pen plotter and HP-GL/2 raster device) and the 'HP-GL/2 viewer' is de facto a pseudo plotter type - it does not represent a real plotter type, it is designed for a general viewing (printing, exporting) of the HP-GL/2, HP-RTL or HP-GL files.

Please realize that the devices named as plotters have some evolution history. Formerly all plotters were pen plotters, i.e. they had real physical pens for drawing. Today modern plotters do not have physical pens, they use raster technologies for drawing (e.g. inkjet, laserjet or electrostatic technologies), so they are not pen plotters, they are raster devices and de facto they are large format printers.

As the drawing technology of plotters changed, there was also evolution in used plotter language(s).

For the pen plotters the most used language became so called HP-GL language (Hewlett Packard Graphics Language). Even if the HPGL language became by this way a standard language for pen plotters, de facto it was never a really standardized language and so there can be differences among individual plotter types even for the same instruction.

The successor of the HPGL language is the HPGL/2 language and it is a well standardized language (all HP-GL/2 devices should conform to this standard). In addition most of plotters based on some raster technology (see below) support also so called HP-RTL language (a subset of the PCL language). By this way the HP-RTL language is a raster supplement to the HP-GL/2 language (which is vector oriented like the HP-GL language). So SPLOT supports also the HP-RTL language and partially also the PCL language.

The most important plotter types in SPLOT are 'HP-GL/2 raster device' and 'HP-GL/2 viewer' because most of today modern plotters are HP-GL/2 raster devices (the 'HP-GL/2 viewer' is based on the HPGL/2 raster device engine). Raster devices use some raster technology (inkjet, laserjet, electrostatic) and have no physical pens.

All other plotter types listed in SPLOT are pen plotters (pen plotters have physical pens). 'HP-GL/2 pen plotter' supports all pen plotter devices using HP-GL/2 language. All other pen plotters are HPGL (old format, not HPGL/2) pen plotters.

In contradistinction to my competitors the SPLOT software is not only a HPGL/2 or HPGL viewer, it tries to act as an exact plotter simulator. For example if you will plot some plot file on a raster device and the same plot file on a pen plotter you will get different results. And SPLOT program enables you to view these results, i.e. it enables you to view the plot file exactly as it will be plotted on a particular plotter type (device).

The only exception is the 'HP-GL/2 viewer' plotter type which serves as a general viewer for plot files (i.e. likewise as my competitors). This plotter type is based on the HP-GL/2 raster device engine, it has support also for the old HP-GL instructions (some old HP-GL instruction are no more part of the HP-GL/2 language) and it has so called 'search extents capability' which enables to automatically find a proper paper size in cases where PS (Paper Size) instruction is missing in the plot file. Such behaviour enables comfortable viewing of most plot files, however such behaviour does not conform to a behaviour of a real plotter.

Because the HP-GL/2 language is a standardized language (all HP-GL/2 devices should conform to this standard) there are used only two basic HP-GL/2 plotter types differing by used technology - HP-GL/2 raster device and HP-GL/2 pen plotter. And because the old HP-GL (not HP-GL/2) language is not standardized (see above), there are offered more HP-GL pen plotters. These offered HPGL models are representative, most of another existing HPGL pen plotters are compatible with some of these types. Generally the HPGL pen plotter types in SPLOT are dedicated to owners of such plotter types. Most of users selects some of the HP-GL/2 plotter types (mostly HP-GL/2 raster device), for users requiring general plot files viewing is the best choice the HP-GL/2 viewer (and so it is the default plotter type in SPLOT).

Please note that the 'HP-GL/2 viewer' term is an abbreviation, in fact it is HP-GL, HP-GL/2 and HP-RTL (and partially PCL) viewer.