laser-lovers@uw-beaver (04/10/85)
From: sun!tut@ucb-vax.arpa (Bill Tuthill) DITROFF Design Guide With the increasing popularity of device-independent troff for laser printers, it's important to set design standards for the character set. The standard, of course, is old-style TROFF for the CAT/4; ideally, DITROFF should be upwardly compatible with TROFF. (The exception is that nobody cares about the Bell symbol \(bs anymore, since AT&T has a new logo.) So if in doubt, run "troff -a" to test formatting behavior. \| 1/6 em space; must be in width table of every alphabetic font \^ 1/12 em space; must be in width table of every alphabetic font \' synonym for \(aa (acute accent) \` synonym for \(ga (grave accent) \_ synonym for \(ul (underline) \(ru rule - must be on baseline; about 1n wide \(ul underline - somewhat below baseline; about 1n wide \(rn root en - above tallest character; about 1n wide \(br box rule - aligns with \(ul on bottom and \(rn on top \(vr vertical rule - aligns with \(ru and \(rn (optional character) = current font equals | + current font plus | may be slanted in italics \- current font minus | \(eq special font equals | \(pl special font plus | \(mi special font minus | \(mu special font multiply | must all be same width \(di special font divide | \(!= special font not equals | \(+- special font plus/minus | \(== exactly equals | \(<= less than or equal | \(>= greater than or equal | must all be same width \(ap approximates | \(~= approximately equal | ** math star (low down) \(ff ff ligature | \(fi fi ligature | \(fl fl ligature | must be in width table if ligatures in font \(Fi ffi ligature | \(Fl ffl ligature | \(.. umlaut (two dots) | \(hc hacek (high small v) | \(bv breve (curved u line) | \(ma macron (long overbar) | optional accent marks (all new) \(cp cap (curved cap line) | \(ui undotted i | \(uj undotted j | \(AE AE ligature | \(OE OE ligature | \(ae ae ligature | \(oe oe ligature | optional Scandinavian ligatures (all new) \(O/ O slash | \(o/ o slash | \(Ao A with circle | Then there are the big bracket building characters, which are essential if mathematics are to come out correctly. Here is a troff source file that tests big braces, parentheses, and brackets at a single point size. It should be run at every point size; the example tests 12 point. .if \nS .ps \nS .sp 1i \b'\(lt\(lk\(lb' x \b'\(rt\(rk\(rb' .sp 1i \b'\(lt\(bv\(lb' x \b'\(rt\(bv\(rb' .sp 1i \b'\(lc\(bv\(lf' x \b'\(rc\(bv\(rf' % troff -rS12 testfile Bill Tuthill