The  dpy  directory contains source for the graphics support in the ROM
monitor.  This support provides terminal emulation which appears like a mix
of the Tek 4014 (for graphics applications) and an ANSI standard terminal
(ANSI X3.64, Additional Controls for Use with ASCII).

The character font is in subdirectory "gallant", which is the name of the
font.  It was designed by hand by Vaughan Pratt.  

The font is not stored in ROM in its full-blown form; rather, it is compressed
by eliminating duplicated rows and by packing the bits together (only 12 bits
per row are used, tho 16 are stored in the uncompressed form).  The "compress"
and "expand" programs are used to transform the font.

Compress simply #includes the original font file, and contains code which
creates gallmash.c, which defines the compressed font, complete with SCCS
header comments and such.  Expand includes both the original and compressed
font files, expands the compressed one into RAM, and compares the two.

The compressed font file (the gallmash.c file output by compress) is the one
which is included by the actual ROM code.

The textual output code has been hand-optimized to operate at high speeds
in order that we can keep up at high baud rates in transparent mode, and to
generally avoid wasting time while filling the screen with direct 68000
output.  If you make extensive changes, or move to a new compiler, it would
be a good idea to look at the generated code from <fwritechar> on down,
and figure the path length.  Try to avoid multiplies in the inner loop --
I did and it went from 2400 to 9600 baud.

@(#)README 1.1 83/09/16 Copyright (c) 1983 by Sun Microsystems, Inc.
