In addition to control words in brackets [], control lines
(with a '-' in the control column) can hold genuine PostScript
code.
For example, the following PRINT scheme produces a gray 3 cm x 3 cm
square:
11 *PRINT 12,19
12 - include PS.DEV / not necessary if PS.DEV is default in SURVO.APU
13 *A shaded square:
14 & 7 (empty lines to have space for the square)
15 - /edge 3 2.54 div 72 mul def[LF]
16 - gsave currentpoint newpath moveto edge 0 rlineto 0 edge rlineto[LF]
17 - edge neg 0 rlineto closepath 0.5 setgray fill grestore[LF]
18 *
19 *The story continues...
Please, note that lines 15-17 containing pure PostScript code have to
be terminated by line feeds defined as [LF] in PS.DEV .
Also the brackets [] appearing in PostScript arrays have to be replaced
by control codes [LB] for '[' and [RB] for ']'.
Otherwise PostScript code can be written in print lists in a normal way.
P = More information on PostScript printing
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