struct mem_act_data
{
  LONG    ad_id;
  LONG    ad_cols;
  LONG    ad_rows;
  LONG    ad_xpos;
  LONG    ad_ypos;
  LONG    ad_size;
  LONG    ad_bytes;
  LONG    ad_tval;
  LONG    ad_tlen;
  LONG    ad_toon;
  LONG    ad_tooc;
  LONG    ad_mode;
  UQUAD   ad_fill;
  UQUAD   ad_tsgr;
  UQUAD   ad_tact;
  UQUAD  *ad_treg;
  UBYTE  *ad_ereg;
  UBYTE  *ad_eend;
  void *(*ad_mmfp)(void *, const void *, size_t);
  void  (*ad_clrfp)(void *, LONG, LONG);
  void  (*ad_scrfp)(void *, LONG);
  void  (*ad_oplfp)(void *, LONG);
  void  (*ad_opcfp)(void *, LONG);
  void  (*ad_ucbfp)(void *, UQUAD *);
  void  (*ad_uokfp)(void *, LONG);
  void   *ad_udata;
  LONG    ad_tab[QDEV_MEM_PRV_TERMTAB];
  UBYTE   ad_exp[QDEV_MEM_PRV_TERMEXP];
  UBYTE   ad_buf[QDEV_MEM_PRV_TERMMIN];
};

ad_id    -  Terminal identification val. as defined in QDEV_MEM_PRV_TERMID.

ad_cols  -  Total terminal columns.

ad_rows  -  Total terminal rows.

ad_xpos  -  Current cursor column. Please note that this value may be found
            out of  range for a brief moment when  examined directly during
            'Write()' that just takes place!

ad_ypos  -  Current cursor row. Please  note that  this value  may be found
            out of  range for a brief moment when  examined directly during
            'Write()' that just takes place!

as_size  -  Real size of the  'ad_buf'  area. This value is always multiple
            of 'sizeof(UQUAD)'.

ad_bytes -  Logical size of  terminal on per byte basis(ad_cols * ad_rows).

ad_tval  -  Temporary ANSI sequence parameter collection. This is used when
            parsing the sequence.

ad_tlen  -  Size  of the 'ad_tab' array at  this very moment. No. of params
            collected.

ad_toon  -  Out-of-node  parameter bitfield.  This is used  to track params
            that were left without value, like: ESC[;6H where -line- param.
            was ommited, so it is possible to use  'ad_tab[0]' as -column-.

ad_tooc  -  Out-of-node  bit counter. Counter  gets shifted 1 bit left each
            time parameter switch(';') is detected.

ad_mode  -  Basic  terminal  modes as  flags such  as LNM, AWM, AWS and G1.

ad_fill  -  Terminal  fill pattern. This is a  bitfield and character store
            at the same time.

ad_tsgr  -  Terminal  SGR  tracker. Used when  dealing with  non-terminated
            sequences where cursor is usually rewinded to particular place.

ad_tact  -  Terminal SGR  active tracker. This  only tracks activators that
            are then cleared after each write cycle.

ad_treg  -  Terminal tracking register is reponsible  for keeping an eye on
            last byte,  so position change  can be  easily noticed  just by
            comparing the addresses.

ad_ereg  -  Sequence expansion start  ptr that is mostly tied to  'ad_exp'.

ad_eend  -  Sequence expansion end pointer that tells how big is the stream
            of sequences for this very terminal byte.

ad_mmfp  -  Memory move function pointer. By default points at 'memmove()',
            and the argument template is UNIX-like. This FP cannot be NULL!

ad_clrfp -  Terminal  clear function pointer. The  routine assigned to this
            FP  is responsible for clearing parts of the terminal. Argument
            template is: 'ad_clrfp(ad, start, end)' where 'ad' is the term.
            area pointer, 'start' is the absolute byte to start clearing at
            and 'end' is the absolute byte to stop clearing at. Function is
            protected from overflows. This FP cannot be NULL!

ad_scrfp -  Terminal scroll function pointer. This routine allows to scroll
            on  line-by-line-from-top-or-bottom basis only. The template is
            as follows: 'ad_clrfp(ad, lines)' where  'ad' is terminal stuff
            and 'lines' amount of lines to scroll. Note that 'lines' can be
            negative, so that scroll takes place the other way around. This
            FP cannot be NULL!

ad_oplfp -  Insert/delete  lines  function pointer. This  routine allows to
            insert or delete lines and thus possibly scroll the terminal at
            any point according to curr. coords(ad_xpos, ad_ypos). Template
            and restrictions same as in 'ad_scrfp'.

ad_opcfp -  Insert/delete  characters function pointer. This routine allows
            to  insert or  delete characters in  a given line  according to
            curr. coords(ad_xpos, ad_ypos). Template: 'ad_opcfp(ad, chars)'
            where 'chars'  can be negative which means delete. This FP must
            not be NULL!

ad_ucbfp -  Usercode function pointer of template: 'ad_ucbfp(ad, termbyte)'
            This  callback will be called whenever  ASCII character was put
            to the terminal. Remember  though that code  pointed to by will
            be executed  as pseudo-interrupt which  should be  treated like
            a  software   interrupt  if  terminal  is  being  used  through
            'mem_openifh()'! By default the FP is NULL.

ad_uokfp -  Usercode  function  pointer  of template: 'ad_uokfp(ad, size)'.
            This callback gets  called after the write did finish. This may
            also  be executed from  under the pseudo-interrupt! By  default
            the FP is NULL.

ad_udata -  General  purpose user pointer as passed to the 'ad_ucbfp()' and
            'ad_uokfp()'. Set to NULL by default.

ad_tab   -  ANSI sequence parameter table.

ad_exp   -  ANSI sequence expasion buffer that is used when reading off the
            terminal.

ad_buf   -  Terminal char space where each "byte" is an UQUAD that combines
            bitfield and real character.