!!!!!!!!!!!!!!!!!  Video Terminal Interface  !!!!!!!!!!!!!!!!
! Terminal mode options (defined in UTIL)
!%constinteger            SINGLE=1<<2, NOECHO=1<<0, NOTERMECHO=1<<1,
!                         NOPAGE=1<<3
constinteger             SPECIALPAD=1<<13
constinteger             SCREENMODE={single+}notermecho+nopage{+specialpad}
! Video FUNction/MODE flag values:-
constinteger             INTENSE=1, REVERSE=2, UNDERLINE=4, BLINK=8,
                         GRAPHICAL=16, SHADE=31
constinteger             FULLSCROLL=64, ANYSCROLL=128;  !FUN only
constinteger             NOSCROLL=64, FREEZE=128;       !MODE only
recordformat             WININFO(byteinteger  top,rows,left,cols,
                                                row,col,fun,mode)
external record (wininfo)spec   VDU;  !full-screen frame
external record (wininfo)spec   WIN;  !current frame
external integer spec    INSERTPOS
!
external routine spec    CLEAR LINE alias  "vtcrol"
external routine spec    CLEAR FRAME alias  "vtcframe"
external routine spec    SCROLL alias  "vtscroll"(integer  t,b,n)
external routine spec    SELECT INPUT alias  "vtselin"(integer  n)
external routine spec    SELECT OUTPUT alias  "vtselout"(integer  n)
external routine spec    PRINT SYMBOL alias  "vtpsym"(integer  sym)
external routine spec    VT AT alias  "vtsetcursor"(integer  row,col)
external routine spec    GOTOXY alias  "vtgotoxy"(integer  x,y)
external routine spec    SET MODE alias  "vtsetmode"(integer  m)
external routine spec    SET SHADE alias  "vtsetshade"(integer  s)
external routine spec    SET FRAME alias  "vtsetframe"(integer  t,r,l,c)
external routine spec    HILIGHT(integer  k)
external routine spec    LOLIGHT(integer  k)
external routine spec    PUSH FRAME alias  "vtpush"
external routine spec    POP FRAME alias  "vtpop"
external routine spec    SWOP FRAME alias  "vtswop"
external routine spec    SET VIDEO MODE alias  "vtsetvideo"(integer  mode)
external routine spec    READ SYMBOL alias  "vtrsym"(integername  k)
external integerfn spec  NEXT SYMBOL alias  "vtnsym"
external routine spec    SKIPSYMBOL alias  "vtssym"
external routine spec    PRINT STRING alias  "vtpstring"(string (255) s)
external routine spec    NEWLINE alias  "vtnl"
external routine spec    NEWLINES alias  "vtnls"(integer  i)
external routine spec    SPACE alias  "vtsp"
external routine spec    SPACES alias  "vtsps"(integer  i)
external routine spec    WRITE alias  "vtwrite"(integer  v,p)
external routine spec    READ alias  "vtread"(integername  v)