300(1) 300(1)NAME 300, 300s - filter text containing printer control sequences for a DASI terminal SYNOPSIS 300 [+12] [-half-line-units] [-dtab-delay,line-delay,char-delay] 300s [+12] [-half-line-units] [-dtab-delay,line-delay,char-delay] ARGUMENTS +12 Permits use of 12-pitch, 6-lines-per-inch text. DASI 300 terminals normally allow only two combinations: 10-pitch, 6 lines per inch or 12-pitch, 8 lines per inch. To obtain the 12-pitch, 6-lines-per-inch combination, you should turn the PITCH switch to 12 and use the +12 option. -dtab-delay,line-delay,char-delay Specifies delay values for tabs (tab-delay), long line length (line-delay), and long strings of nonblank, nonidentical characters (char-delay). DASI 300 and 300s terminals sometimes produce peculiar output when faced with too many tab characters, very long lines, or long strings of nonblank, nonidentical characters. The 300 and 300s commands use delay values to adjust the timing of the output in these cases. Because terminal behavior varies according to the specific characters printed and the load on a system, you may need to override the default delay values, which are 3, 90, and 30, to get a satisfactory result. You can omit a value for line-delay and char-delay, or for just char-delay, to use their default delay values. The commands insert one null (delay) character in a line for every set of tabs specified by tab-delay and for every contiguous string of nonblank, nontab characters specified by line-delay. If a line is longer than the number of bytes specified by line-delay, the commands perform the following calculation to determine the number of nulls to insert at the end of that line: nulls = 1+(total-line-length)/20 If tab-delay or char-delay has a value of 0, the commands use two null bytes per tab or character, respectively. An option of -d0,1 may be appropriate for printing a C program that has many levels of indentation, and an option of -d3,30,5 may be appropriate for printing files such as /etc/passwd. January 1992 1
300(1) 300(1)Note that the values supplied with the -d option interact with the prevailing carriage return and line- feed delays. The stty(1) modes nl0 and cr2 or nl0 and cr3 are recommended for most uses. -half-line-units Specifies the size of half-line spaces, thus allowing for individual taste in the appearance of subscripts and superscripts. A half-line is, by default, equal to 4 vertical plot increments. Because each increment equals 1/48 of an inch, a 10-pitch line feed requires 8 increments, while a 12-pitch line feed requires only 6. For example, you can make nroff half-lines to act as quarter-lines by using -2. You can also obtain appropriate half-lines for the 12-pitch, 8-lines-per- inch combination by setting the PITCH switch to 12 and by using the option -3 alone. DESCRIPTION 300 supports special functions and optimizes the use of the DASI 300 (GSI 300 or DTC 300) terminal; 300s performs the same functions for the DASI 300s (GSI 300s or DTC 300s) terminal. The 300 and 300s commands convert half-line forward, half-line reverse, and full-line reverse motions to the correct vertical motions. The commands also draw Greek letters and other special symbols and permit convenient use of 12-pitch text. The commands reduce printing time up to 70 percent and can be used to print equations neatly as in the following sequence: neqn file... | nroff | 300 The neqn names of, and resulting output for, the Greek and special characters supported by these commands are shown in greek(5). You can use these commands with the nroff -s option or .rd requests to halt printing temporarily so that you can insert paper manually or change fonts in the middle of a document. Instead of pressing the RETURN key in these cases, press the line-feed key to continue printing. In many (but not all) cases, the following two command lines are equivalent: nroff -T300 files nroff files | 300 2 January 1992
300(1) 300(1)Similarly, in many (but not all) cases, the following two command lines are equivalent: nroff -T300 -12 files nroff files | 300 +12 Thus, you can often avoid using 300 and 300s unless special delays or options are required; in a few cases, however, the additional movement optimization of these commands may produce better-aligned output. WARNINGS If your terminal has a PLOT switch, set it to the ``on'' position before using 300. LIMITATIONS Some special characters cannot be correctly printed in column 1 because the print head cannot be moved to the left from there. If your output contains Greek or reverse line feeds, use a friction-feed platen instead of a forms tractor. Although the forms tractor is good enough for drafts, it has a tendency to slip when reversing direction. This slippage causes distortion of Greek characters and misalignment of the first line of text after one or more reverse line feeds. FILES /usr/bin/300 Executable file /usr/bin/300s Executable file SEE ALSO 450(1), eqn(1), mesg(1), nroff(1), stty(1), tabs(1), tbl(1), tplot(1G) greek(5) in A/UX Programmer's Reference January 1992 3