List of supported HP-GL commands:         Date: 92/10/20
=================================

hp2xx emulates a subset of the Hewlett-Packard 7550A plotter.
The following manual was used as reference for command definitions:

     [1] "HP 7550A Interfacing and Programming Manual"



Not all commands are supported. Among the non-supported commands
are those which do not really apply to a software emulator, like:

   o commands affecting the communication between plotter and host computer,

   o commands for changing the behaviour of a real plotter, like
     plotting speed etc.,

   o commands for the control of plotter memory allocation,

   o commands causing various plotter outputs.


Other non-supported commands would be desirable, but were left out
due to their inherent complexity (or just because nobody pushed me, :-) ).
Among those are:

   o commands for font (character set) management.
       Since there is only one font built into hp2xx, there is
       no point in providing font switching etc.

   o windowing/clipping and rotation

   o polygon and box filling commands


The remainder of this file tabulates all HP-GL commands listed on
pages 1-2 to 1-4 in [1] and marks them as either

      not applicable       (.),
      ignored              (-), or
      supported            (+)

  I use the label "supported" when I think the command is fully supported
only in the context of the already implemented commands. In general,
you should have absolutely no problem with this class of commands.

  Though there still are unsupported commands, this does not mean that
you might have trouble using hp2xx. Nowadays, most HP-GL files are
machine-generated, e.g. by CAD or DTP programs. These tend to make use
of just a simple subset of HP-GL. To my experience, chances are high
that hp2xx will give you the picture you want!




HP-GL|s n| Description & Remarks
Cmd  | i |
=====|===|========================================================
 AA  |+  | Arc Absolute
 AF  |+  | [same as PG]
 AH  |+  | [same as PG]
 AP  |  .| Automatic pen operations
 AR  |+  | Arc Relative
 AS  |  .| Acceleration select
     |   |
 BF  | - | Buffer Plot
 BL  |+  | Buffer Label
     |   |
 CA  | - | Designate alternate character set
 CC  | - | Character Chord angle
 CI  |+  | Circle
 CM  | - | Character selection mode
 CP  |+  | Character plot
 CS  | - | Designate standard character set
 CT  | - | Chord tolerance
 CV  | - | Curved line generator
     |   |
 DC  |  .| Digitize clear
 DF  |+  | Default
 DI  |+  | Absolute direction
 DL  | - | Define downloadable character
 DP  |  .| Digitize point
 DR  |+  | Relative direction
 DS  | - | Designate character into slot
 DT  |+  | Define label terminator
     |   |
 EA  | - | Edge rectangle absolute
 EP  | - | Edge polygon
 ER  | - | Edge rectangle relative
 ES  |+  | Extra space
 EW  | - | Edge wedge
     |   |
 FP  | - | Fill polygon
 FS  |  .| Force select
 FT  | - | Fill type
     |   |
 GC  |  .| Group count
 GM  |  .| Graphics memory
     |   |
 IM  | - | Input mask
 IN  |+  | Initialize
 IP  |+  | Input P1 and P2
 IV  | - | Invoke character slot
 IW  | - | Input window
     |   |
 KY  |  .| Define key
     |   |
 LB  |+  | Label
 LO  |+  | Label origin
 LT  |+  | Line type
     |   |
 NR  |  .| Not ready (unload page)
     |   |
 OA  |  .| Output actual position and pen status
 OC  |  .| Output commanded position and pen status
 OD  |  .| Output digitized point and pen status
 OE  | - | Output error
 OF  | - | Output factors
 OG  |  .| Output group count
 OH  | - | Output hard-clip limits
 OI  |  .| Output identification
 OK  |  .| Output key
 OL  | - | Output label length
 OO  |  .| Output options
 OP  |+  | Output P1 and P2
 OS  | - | Output status
 OT  |  .| Output carousel type
 OW  | - | Output window
     |   |
 PA  |+  | Plot absolute
 PB  |+  | Print buffered label
 PD  |+  | Pen down
 PG  |+  | Page feed
 PR  |+  | Plot relative
 PT  | - | Pen thickness
 PU  |+  | Pen up
     |   |
 RA  | - | Fill reactangle absolute
 RO  | - | Rotate coordinate system  [use option -r instead!]
 RP  | - | Replot
 RR  | - | Fill reactangle relative
     |   |
 SA  | - | Select alternate character set
 SC  |+  | Scale
 SI  |+  | Absolute character size
 SL  |+  | Character slant
 SM  |+  | Symbol mode
 SP  |+  | Select pen
 SR  |+  | Relative character size
 SS  | - | Select standard character set
     |   |
 TL  |+  | Tick length
     |   |
 UC  |+  | User-defined character
 UF  | - | User-defined fill type
     |   |
 VS  |  .| Velocity select
     |   |
 WD  |+  | Write to display
 WG  | - | Fill wedge
     |   |
 XT  |+  | X-Tick
     |   |
 YT  |+  | Y-Tick

