) ▁S LT ▁Local ▁Storage , ▁used ▁by ▁the ▁micro code . ▁ ▁Standard ▁Fe atures ▁Com mer cial ▁instruction ▁set ▁Att achment ▁for ▁ 1 0 5 2 ▁Pr inter - Key board ▁Model ▁ 7 ▁ ▁Optional ▁Fe atures ▁Scient ific ▁or ▁universal ▁instruction ▁set ▁Byte ▁multiple x er ▁channel ▁or ▁selector ▁channel ▁( one ▁of ▁either ) ▁Storage ▁protection ▁Direct ▁control ▁( with ▁external ▁interrupt ) ▁or ▁external ▁interrupt ▁( alone ) ▁Timer ▁( line - fre quency ▁type ) ▁IBM ▁ 1 4 0 1 / 1 4 6 0 ▁compatibility ▁ 1 4 0 1 / 1 4 4 0 / 1 4 6 0 ▁D OS ▁compatibility ▁ 1 4 4 0 ▁compatibility ▁System / 3 6 0 ▁Model ▁ 2 0 ▁mode ▁CPU - integr ated ▁attach ments ▁for : ▁One ▁ 1 4 0 3 ▁Pr n ter ▁Model ▁ 2 ▁or ▁ 7 ▁As ▁many ▁as ▁four ▁ 2 3 1 1 ▁Disk ▁Storage ▁D riv es ▁Model ▁ 1 ▁( with ▁file ▁scan ▁feature ) ▁One ▁ 2 5 4 0 ▁Card ▁Read ▁P unch ▁Model ▁ 1 ▁( with ▁column ▁binary ▁feature ▁and ▁p unch ▁feed ▁read ▁control ) ▁One ▁ 2 5 6 0 ▁Multi - function ▁Card ▁Machine ▁Model ▁A 1 ▁( for ▁Model ▁ 2 0 ▁mode ; ▁also ▁for ▁System / 3 6 0 ▁mode ▁[ read / p unch ▁only ] ▁if ▁the ▁ 2 5 4 0 ▁em ulation ▁feature ▁CPU - integr ated ▁communic ations