HP PCL/PJL reference (PCL 5 Printer Language) - Technical Reference Manual Part II

EN PE, Polyline Encoded 20-41
When using PE (in the default relative mode), the application program
does not know the current pen location after printing a label (normally,
the current pen location is updated to the end of the label.) If this
presents a problem in your program, follow these steps.
1 Create a flag called "lost" in your program.
2 After labeling (or any command which updates the current pen
location), set lost to true.
3 If lost = true at the beginning of the PE command, use an
absolute flag for the first coordinate pair only (subsequent
coordinates are interpreted as relative).
4 Set lost to false.
Note At the beginning of your application program, set lost to true. Then,
specify the next coordinate in absolute mode (PA or PE=).
When converting and encoding data, note the following.
z n DIV 64 = n.shift right.6 bits. You can optimize your application
by shifting 6 bits to the right since shifting is faster than division.
z n MOD 64 = n.AND.63. The number is logically AND'd with 63.
Example: Using the PE Command
The following BASIC program converts three relative real coordinates
to base 64.
``10 LPRINT CHR$(27);"E"; 'Reset the Printer.''
``20 LPRINT CHR$(27);"%0B"; 'Enter HP-GL/2 Mode.''
``30 LPRINT "IN;SC1,20,1,20,1;SP1;PU5,5;";''
``40 PRINT "Input number of fractional decimal places in data" ''
``50 INPUT F 'In this example, 2 decimal places (line 290).''
``60 'Calculate Number of Fractional Binary Bits ''
``70 F = F * 3.33 ''
``80 F = INT(F) ''
``90 A = F ''
``100 IF F >= 0 THEN F = 2*ABS(F) ELSE F = 2*ABS(F)+1 ''
``110 F = 191+F ''
``120 LPRINT #1, "PE>"+CHR$(F) ''