. . .
Do: Loop While INKEY$ = ""  '1st Do Loop

'Print INKEY$;

Do                          '2nd Do Loop
 something
Loop While INKEY$ = ""

something else
...

DO
 s$ = INKEY$
WHILE s$ = ""

PRINT s$

 'INKEY$-Play.BAS
 ' Seeks to resolve odd Inkey$ behaviour
 dim integer I = 0
 cls
   
 do          '1st Do loop
   S$ = Inkey$
   I = I + 1
   Text 0, 100, "Press a key to move on " + Str$(I), "LB",2,1 ,RGB(green)
   Pause 500   'Just to slow it down
 loop while S$ = ""

 'S$ = ""
 I = 0
 do          '2nd Do loop
   T$ = Inkey$ 'Changed to T$ incase repeat of S$ was a problem
   I = I + 1
   text 0, 300, "Press a key to end " + str$(I), "LB", 2, 1, RGB(Cyan)
   pause 500   'Just to slow it down
 loop while T$ = ""

End

do
   i$ = inkey$
 loop until i$<>""

 DO : LOOP UNTIL INKEY$ = ""
 select case i$
...

option explicit
option default integer
dim pressed(3)
settick 25,keyint
dim i
do
for i=0 to 3
  if pressed(i) then
    text i*mm.info(fontwidth),10, chr$(pressed(i))
  else
    text i*mm.info(fontwidth),10, chr$(32)
  endif
next i
loop

'routine to monitor keypresses and maintain a list of up to
'four  that are pressed at any one time
sub keyint
local i,j
local clearkey
local keys(7)
' take a local copy of the keydown function
for i=0 to 4
  keys(i)=keydown(i)
next i
if keys(0) > 4 then keys(0)=4 'limit of 4 keys can be pressed

' first clear any keys that were pressed that are no longer
for i=0 to 3
  clearkey=1
  if pressed(i) then
    for j=1 to keys(0)
      if keys(j)=pressed(i) then
        clearkey=0 'still pressed so don't clear
        keys(j)=0 'remove the key so it isn't used as a new press
      endif
    next j
  endif
  if clearkey then
    pressed(i)=0
  endif
next i
' now establish if there are any new key pressed
for i=0 to 3
  if pressed(i) then continue for 'slot already used
  for j=1 to keys(0)
    if keys(j) then
      pressed(i)=keys(j)
      keys(j)=0 'make sure a key isn't processed twice
    endif
  next j
next i
end sub

 'KEYDOWN Play.BAS
 '
 'Plays with the use of KEYDOWN
 
 Dim Integer I
 
 cls
 print "Press left, right, space or ESCAPE key"
 'MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM - Start of main loop
 do
   ' test for keypresses
   if keydown(0) then    'At least 1 key pressed
     IF TIMER > 200 THEN  'EXPERIMENTAL Not essential but change to alter response to subsequent key presses
       TIMER = 0
       'print Keydown(0); "  ";    'KEYDOWN(0) is the number of keys pressed
       for I = 1 to keydown(0)    'Only interested in 1 and above
         'print Keydown(0); "  ";keydown(i);"  ";
         'See Appendix F of manual for codes
         if keydown(I) = 27 then Exit Do     'ESCAPE so bail out
         if keydown(I) = 130 then GoLeft     'Left
         if keydown(I) = 131 then GoRight    'Right
         if keydown(I) = 32  Then GoSpace    'Space bar
         ' . . .
       next I
     endif
   End If
 Loop
 'mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm - end of main loop
 Print "Goodbye"
End
 
Sub GoLeft
 print "Left"
End Sub
 
Sub GoRight
 print "Right"
End Sub
 
Sub GoSpace
 print "Space"
End Sub

 'INKEY$_Play v2.BAS
 '
 'Plays with the use of INKEY$
 
 'TassyJims example
 '  do
 '   i$ = inkey$
 '  loop until i$<>""
 '
 '  DO : LOOP UNTIL INKEY$ = ""
 '  select case i$
 '  ...
 '
 Dim Integer I
 dim String In
 cls
 print "Press left, right, space or ESCAPE key"
 'MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM - Start of main loop
 do
   do
     ' test for keypresses
     In = INKEY$
   loop Until In <> ""
   DO : LOOP UNTIL INKEY$ = "" 'This is Jim's game-changer
   Select Case asc(In)
     Case 27     'ESCAPE
       Exit Do
     Case = 130  'Left
       GoLeft
     Case 131    'Right
       GoRight
     Case 32     'Space bar
       GoSpace        
   End Select
   'In = ""  Not necessary as it gets set to "" in the first pass in the DO
 Loop
 'mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm - end of main loop
 Print "Goodbye"
End
 
Sub GoLeft
 print "Left"
End Sub

Sub GoRight
 print "Right"
End Sub
 
Sub GoSpace
 print "Space"
End Sub