NEC Corp, Hitachi Ltd and Toshiba Corp all say that 4M-bit memory chip output has reached its peak, and all further expansion of output of dynamics will be of 16M-bit parts: NEC said the company will start volume production of 16Ms in late 1994 after 4Ms peak at 10m a month next month, Hitachi has set the monthly ceiling figure for 4Ms at 11m, and Toshiba at 8m; all three plan to raise their 16m output to 2m a month by the end of the year; they are presently doing between 500,000 and 1m 4Ms each.