Bob, To me it appears that the two files are similar. When I look at the two files I see the same types of commands except the HPGL commands are separated by semicolon.
In my PCL5 book from HP it defines HP-GL as a vector graphics language. (In fact most of my old dials are written in it.) It is a language separate from the PCL language of printer that are escape character control sequences, for example esc$l55P set the lines per page to 55. HPGL seems to be a plotter like language as it has the concept of pens and plotter units. It also has scaling factor, paper coordinates, clipping, rotations, circles, rectangles, etc. The PA command is PLOT ABOSULTE which means to move the pen to an absolute x.y coordinate. A line is drawn if the pen is down. PR being PLOT RELATIVE from when the pen is. My guess is that HPGL is an extension of older HP plotter languages. I also think that .PRN is just the attbitrary Windows extension for a file that holds data that was destined for a printer of any type. .PLT is a semi standard for plotter files, and HPL, HPG, HGL are for HP printers that may or may not have HPGL, and may or may not be readable by various HPGL input filters. ++ron ----- Original Message ----- From: Robert Terwilliger <[EMAIL PROTECTED]> To: <[email protected]> Sent: Saturday, April 08, 2000 7:01 AM Subject: More on Plotting and Printing > Hi All, > > I hope someone will be able to clarify the differences between HPGL, > prn, and plt files, and how they are meant to be used. HPGL and prn are > both text based files. > > Here is a snip from a HPGL file. The commands "PU" and "PD" stand for > "Pen Up" and "Pen Down" respectively. It would be logical that "PA" > stands for "Pen Advance" followed by the XY coordinates. > > PU;PA 3486, 5524; > PD;PA 8344, 6729; > PU;PA 8344, 1911; > PD;PA 8344, 6729; > PU;PA 3486, 706; > PD;PA 20, 1399; > > Here is a snip from a prn file produced by printing a DeltaCad drawing > to a HP plotter on File. The format is completely different. > > 370,2005PRPD55,0PAPU-345,2000PRPD-50,0PAPU-370,1995PRPD-55,0PAPU-400,1990PRP D-50,0PAPU-425,1985PRPD-55,0,0,-5,30,0PAPU-475,1975PRPD-5,0PAPAPU-470,1985PR PD-5,0,5,-5,-20,0PAPU-510,1975PRPD40,0PAPU-490,1970PRPD-35,0PAPU-510,1965PRP D-35,0PAPU-560,1960PRPD35,0PAPU-545,1955PRPD-35,0PAPU-595,1950PRPD35,0PAPU-5 80,1945PRPD-35,0PAPU-595,1940PRPD-40,0,0,-5,20,0PAPU-630,1930PRPD-5,0PAPAPU- > > I do not know what a plt file looks like, nor do I know if it's just an > alternate extension for a prn file - but I doubt it. > > Can anyone help? > > ------------- > > Also, referring to the discussion of using printouts as templates, be > aware that printers do not all scale accurately, nor do they all produce > an accurate aspect ratio. In my experience my HP LaserJet III did both > perfectly. That printer has since gone where good printers go when they > die. My new HP OfficeJet 1175C (an ink jet as opposed to a laser jet) > does not produce an accurate aspect ratio. > > Best, > > Bob >
