CDM                                  SysV                                  CDM




NAME
     cdm - changes the display mode

SYNOPSIS
     cdm [-p 1 | 8 | 7]

DESCRIPTION
     The cdm command changes the color mode of the hardware.  This affects the
     colors that the DM and other pseudo color applications use.  You
     normally use this command in preparation for running a true color
     application, which requires a workstation with at least 24 planes, in a
     window. When you run an application that uses 24-plane true color, you
     must restrict pseudo color applications (including the DM) to only two
     colors (normally black and white).  When you run an application that uses
     21-plane true color (shared color mode), you can specify 7-bit pseudo
     color for the DM.  Since the DM uses only four planes for pseudo color,
     all of the DM colors are unchanged in shared color mode.

     At login, the default is cdm (with no options), which instructs the
     hardware to use the highest number of pseudo color planes (normally 8)
     when drawing colors.  In this mode, the DM uses several colors for window
     banners, window background, and text.

     Note that the device must support the options you specify.  Otherwise,
     the DM gives an error message, "wrong display hardware".  This command
     cannot be used at all for devices with less than 24 planes or for devices
     with multiple color maps.  Devices with 24 planes (the DN590) can use the
     -p 1 and -p 8 options.  Devices supporting shared color mode can use the
     -p 7 option.

     The cdm command differs from the mono command in that the mono command
     does not affect the hardware in any way.  The mono command simply
     instructs the DM to use black and white for all its drawing operations,
     thus freeing up color slots in the color map.

OPTIONS
     The only option that the cdm command takes is -p n, which allows you to
     specify the number of colors available to the DM and other pseudo color
     applications.  For example, cdm -p 1 causes all pseudo color output to be
     displayed in only two colors. This is necessary so that some application
     can run in true color mode.  When you finish running a true color
     application, you can restore the DM to its original state by issuing the
     cdm -p 8 command.  The default display mode for the DM is four colors for
     window background; four more for window banner background; white for
     banner text; and black for text in DM windows.

     If you do not specify an option, cdm defaults to the highest number of
     pseudo color planes, causing the display to be reset to its original
     state, where existing pseudo color applications work as before.

     -p 1      This causes the DM to put the hardware in a state where the DM
               and all other pseudo color applications draw in only two colors
               (usually black and white).

     -p 8 (default)
               This changes the hardware mode to allow the DM and other
               applications to use pseudo color.  The DM's output appears in
               many colors.  This option is currently equivalent to giving the
               cdm command with no options.

     -p 7      This specifies shared color mode, in which both true color and
               pseudo color are available at the same time.  With this option,
               the DM and other pseudo color applications can run in pseudo
               color and true color applications can run in true color
               simultaneously.  In shared color mode, pseudo color has 7 bits
               ;the high-order bit is dropped.  True color has 21 bits (7 red,
               7 green, 7 blue), and the low-order bits are dropped.  128
               colors are available in pseudo color and 8.35 million colors
               are available in true color.


SEE ALSO
     dm(1), scrattr(1)