00309nam a2200121Ia 4500008004100000041001200041082002100053100002500074245003900099260002700138300000800165650001400173231217s9999    xx            000 0 und d  aEnglish  a001.6404  HEL1;2  aHeld, Gilbert, David 0aIBM PC AT: User's reference manual  cNULLbNew Delhi : BPB,  a453  aIBM PC AT