The input format for WRspice is of the free format type. Fields on a line are separated by one or more blanks, a comma, an equal (=) sign, or left or right parenthesis; extra white space is ignored.
A line may be continued to the following line(s) in two ways. If the last character on a line is a backslash character ( \), the ``newline'' is effectively hidden, and the text on the following line will be appended to the current line, however leading white space is stripped from the continuing line. The traditional SPICE line continuation is also available, whereby a line may be continued by entering a + (plus) as the first non-white space character of the following line, WRspice will continue reading beginning with the character that follows.
Device and model names and parameters are case-insensitive, however, unlike other SPICE programs, node names are case sensitive. One should consider this when importing old SPICE files that use textual node names.
Files read by WRspice as circuit descriptions or control directives are text-mode files, in either the UNIX or DOS line termination format. If a character is found in the first (title) line with the most-significant bit set, the read is aborted, as this is taken as binary input, and attempting to read a binary file would generate a cascade or errors or crash the program. Binary characters can exist elsewhere in the file, if necessary for whatever reason.
A name field must begin with a letter and cannot contain any delimiters.
A number field may be an integer field (12, -44), a floating point field (3.14159), either an integer or floating point number followed by an integer exponent (1E-14, 2.65E3), or either an integer or a floating point number followed by one of the following scale factors (case insensitive):
t 1e12 g 1e9 meg 1e6 k 1e3 mil 25.4e-6 m 1e-3 u 1e-6 n 1e-9 p 1e-12 f 1e-15
Letters immediately following a number that are not scale factors are ignored, and letters immediately following a scale factor are ignored. Hence, 10, 10v, 10volts, and 10hz all represent the same number, and m, ma, msec, and mmhos all represent the same scale factor. Thus 1000, 1000.0, 1000hz, 1E3, 1.0e3, 1KHz, and 1k all represent the same number.