Code update..

The code was full of errors, now it is better....

DIM TC AS INTEGER, TANK AS STRING, OLDTC AS INTEGER, LSR AS INTEGER, TCX AS INTEGER
TANK$ = "L20 U10 R10 E10 F10 R10 D10 L20"
TC = 320: LSR = 0
SCREEN 12: CLS : PSET (TC, 478): DRAW "C14" + TANK$: TCX = 456
DO
IF LSR = 1 THEN PSET (OLDTC, TCX + 5), 0: DRAW "D5": PSET (OLDTC, TCX), 12: DRAW "U5": TCX = TCX - 10
IF LSR = 1 AND TCX <= 1 THEN PSET (OLDTC, TCX + 5), 0: DRAW "D5": TCX = 456: LSR = 0:
ARROW$ = INKEY$
SELECT CASE ARROW$
CASE CHR$(0) + CHR$(75): IF TC > 20 THEN PSET (TC, 478), 0: DRAW TANK$: TC = TC - 10: PSET (TC, 478), 14: DRAW TANK$
CASE CHR$(0) + CHR$(77): IF TC < 620 THEN PSET (TC, 478), 0: DRAW TANK$: TC = TC + 10: PSET (TC, 478), 14: DRAW TANK$
CASE CHR$(0) + CHR$(72): OLDTC = TC: PSET (OLDTC, 456), 12: DRAW "U5": LSR = 1
CASE CHR$(27): SYSTEM
END SELECT
LOOP

....UNSEEN