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When I ran the following program using WindX against a Linux or Windows server it worked here:
0010 PRINT 'EL',"2",CHR(9),$02$,"Y"+$0D$, ! Delete key ("Y"
0020 PRINT 'EL',"2",CHR(2),$02$,"A"+$0D$, ! Up arrow ("A")
0030 PRINT 'EL',"2",CHR(0),$02$,"N"+$0D$, ! Left arrow ("N")
0040 WHILE 1
0050 INPUT X$
0060 IF CTL<>0 THEN BREAK ! Press F4 to exit
0070 PRINT "You entered:",X$
0080 WEND
It handled the Delete, Up, and Left arrow as per your email.