' F4Term.bas

open "com1:19200,10000" as #1
dim integer i,j,k,l,m,n,x,y nlines=1, maxLn=300, maxShow, cursorPos
dim string a$,b$,c$,s$,ln$, lines$(maxLn) length 100
dim integer maxLineLen=100, line1=1, showEnd=1, iStart=1

font 2 ' 24 lines by 66 characters
' FONT 1 ' 36 lines by 100 char
maxShow=fix(mm.vres/mm.fontheight)

do
   if loc(#1)>0 then
     a$=getCh$()
   else
     a$=_inkey$()
     if a$>"~" then ' special characters only: End, Home, PgUp, PgDn
     else
       a$="" ' ignore all normal characters (<128) from keyboard
     endif
   endif
   if asc(a$)=27 then ' escape sequence
     doEsc
   elseif asc(a$)=13 then ' carriage return (endShow)
     if nlines<=maxShow then ' screen not yet filled
     else
'        if showEnd=nlines then ' we are showing the last line
'          blit 0,mm.fontheight,0,0,mm.hres,mm.vres-mm.fontheight
'          y=mm.vres-mm.fontheight
'          box 0,y,mm.hres,mm.fontheight,,rgb(black),rgb(black)
'        endif
       y=0: iStart=max(1,nlines-maxShow+1): showLines: showEnd=nlines
     endif
     if showEnd=nlines then ' we are showing the last line, so add one
       s$=str$(nlines)+" "+lines$(nlines)
       text 0,y,s$
       y=y+mm.fontheight
       iStart=max(1,nlines-maxShow+1)
     endif
     if nlines<=maxln then
       nlines=nlines+1: showEnd=nlines
     endif
   elseif asc(a$)=128 then ' Up Arrow
     iStart=max(1,iStart-1): showLines
   elseif asc(a$)=129 then ' Down Arrow
     iStart=min(nlines-maxShow+1,iStart+1): showLines
   elseif asc(a$)=130 then ' Left Arrow (Font 1 36 lines by 100 ch)
     font 1: maxShow=fix(mm.vres/mm.fontheight): iStart=1: showLines
   elseif asc(a$)=131 then ' Right Arrow (Font 2 24 lines by 66 ch)
     font 2: maxShow=fix(mm.vres/mm.fontheight): iStart=1: showLines
   elseif asc(a$)=11 or asc(a$)=137 then ' Page up
     iStart=min(iStart+maxShow,nlines-maxShow+1): showLines
   elseif asc(a$)=12 or asc(a$)=136 then ' Page down
     iStart=max(1,iStart-maxShow): showLines
   elseif asc(a$)=134 then: iStart=1: showLines: ' Home
   elseif asc(a$)=135 then ' End
     iStart=max(1,nlines-maxShow+1): showLines
   elseif a$>=" " and a$<="~" then ' printable
     if len(lines$(nlines))< maxLineLen then
       lines$(nlines)=lines$(nlines)+a$
     endif
   endif
loop

sub doEsc
' handle: 2J-cls 1F,2F-font H-home #;A-up #;B--down
 a$=getCh$()
 if a$="[" then ' second char of escape sequence
   a$=getCh$()
   select case a$
     case "H": goHome
     case "2" ' could be cls or font
       a$=getCh$()
       if a$="J" then
         cls: nlines=1: for i=1 to maxLn: lines$(i)="": next i: y=0
       elseif a$="F" then
         font 2:maxShow=fix(mm.vres/mm.fontheight)
       endif
     case "1" ' font
       a$=getCh$()
       if a$="F" then: font 1: maxShow=fix(mm.vres/mm.fontheight): endif
   end select
 endif
end sub

sub showLines
 showEnd=min(nlines,iStart+maxShow)
 cls: y=0: for i=iStart to showEnd
   s$=str$(i)+" "+lines$(i)
   text 0,y,s$
   y=y+mm.fontheight
 next i
 line1=1
end sub


function getCh$()
 do: loop while loc(#1)=0
 getCh$=input$(1, #1)
end Function  
 
Function _inkey$()
 local ky$
 ky$=inkey$
 if asc(ky$)=27 then ' escape sequence
   ky$=inkey$: ky$=inkey$: ky$=ucase$(ky$)
'    ?ky$;
   If ky$="A" Then: ky$=chr$(128) ' up arrow
   ElseIf ky$="B" Then: ky$=chr$(129) ' down arrow
   ElseIf ky$="C" Then: ky$=chr$(131) ' right arrow
   ElseIf ky$="D" Then: ky$=chr$(130) ' left arrow
   ElseIf ky$="1" Then: ky$=chr$(134) ' home
   ElseIf ky$="4" Then: ky$=chr$(135) ' end
   ElseIf ky$="5" Then: ky$=chr$(136) ' pgup
   ElseIf ky$="6" Then: ky$=chr$(137) ' pgdn
   ' Function keys are ???
   EndIf
 endif
 _inkey$=ky$
end function