UNDO for the Atari ST VolksForth command line

The tool extends the VolksForth "decode" function with an UNDO. If there was a typo in the previous line pressing the UNDO key will re-fetch the last entered line so that it can be edited

Published in VD 3/87 by Bernd Pennemann

 \ Undo for Atari ST                                 cas2013apr05
 Onlyforth

 | $6100 Constant #undo

 : undoSTdecode ( addr pos1 key -- addr pos2 )
   over 0= if
     #undo case? if at? >r >r
                    over #tib @  dup span ! type
                    r> r> at exit then then
   STdecode ;

Input: keyboard  STkey STkey? undoSTdecode STexpect ;

keyboard save