The Change  Bit command  allows one  or more  bits to be  changed in  a
byte to  either *ON ('1') or *OFF  ('0').  The bits are  numbered 1 - 8
with  1 being  the high order  bit.  A  variable must  be specified for
the &RTNBYTE parameter and  all BITn parameters cannot be  specified as
*SAME.

A typical series of commands would be:

            DCL        &RTNBYTE *CHAR LEN(1)
             .
            CHGBIT     BYTE(&BYTE) RTNBYTE(&RTNBYTE) BIT3(*ON)

The &BYTE  value would be moved to  the &RTNBYTE value and  Bit 3 would
be set on.

CHGBIT escape messages you can monitor for
------------------------------------------

None.  Escape messages from based on functions will be re-sent.

CHGBIT Command parameters                             *CMD
-------------------------

   BYTE          A  required  *CHAR LEN(1)  value  for the  byte  to be
                 changed.   A  variable  may  be used.    When  command
                 prompting is  used, you can  expand the length  of the
                 input field by entering & and pressing Enter.

   RTNBYTE       A  required *CHAR LEN(1)  value for  the modified byte
                 to be  returned.    A  variable may  be  used.    When
                 command prompting is  used, you can expand  the length
                 of the  input field by entering &  and pressing Enter.

   BIT1          The value to be changed for Bit 1 (high order).

                 *SAME is the default meaning no change occurs.

                 *ON may be specified to set the bit to '1'.

                 *OFF may be specified to set the bit to '0'.

   BIT2          The value to be changed for Bit 2.

                 *SAME is the default meaning no change occurs.

                 *ON may be specified to set the bit to '1'.

                 *OFF may be specified to set the bit to '0'.

   BIT3          The value to be changed for Bit 3.

                 *SAME is the default meaning no change occurs.

                 *ON may be specified to set the bit to '1'.

                 *OFF may be specified to set the bit to '0'.

   BIT4          The value to be changed for Bit 4.

                 *SAME is the default meaning no change occurs.

                 *ON may be specified to set the bit to '1'.

                 *OFF may be specified to set the bit to '0'.

   BIT5          The value to be changed for Bit 5.

                 *SAME is the default meaning no change occurs.

                 *ON may be specified to set the bit to '1'.

                 *OFF may be specified to set the bit to '0'.

   BIT6          The value to be changed for Bit 6.

                 *SAME is the default meaning no change occurs.

                 *ON may be specified to set the bit to '1'.

                 *OFF may be specified to set the bit to '0'.

   BIT7          The value to be changed for Bit 7.

                 *SAME is the default meaning no change occurs.

                 *ON may be specified to set the bit to '1'.

                 *OFF may be specified to set the bit to '0'.

   BIT8          The value to be changed for Bit 8 (low order).

                 *SAME is the default meaning no change occurs.

                 *ON may be specified to set the bit to '1'.

                 *OFF may be specified to set the bit to '0'.

Restrictions
------------

Because  CHGBIT returns a variable,  the command may only  be used in a
CL program.

Prerequisites
-------------

The following TAA Tools must be on your system:

     SNDESCINF       Send escape information
     SNDESCMSG       Send escape message

Implementation
--------------

None, the tool is ready to use.

Objects used by the tool
------------------------

   Object        Type    Attribute      Src member    Src file
   ------        ----    ---------      ----------    ----------

   CHGBIT        *CMD                   TAACLTN       QATTCMD
   TAACLTNC      *PGM       CLP         TAACLTNC      QATTCL
   TAACLTNR      *PGM       RPG         TAACLTNR      QATTRPG