Abstract: An information processing apparatus includes a plurality of processor boards arranged parallelly on the main board and the DC--DC converters for generating operation voltages for processor devices each disposed between the adjacent processor boards. Further, a metal plate with high thermal conductivity is placed in close contact with an area of each of the processor boards where devices generating a large amount of heat are mounted. Heat dissipating fins are joined to the surface of each of the metal plates so that when the processor boards are mounted on the main board, the heat dissipating fins do not contact the DC--DC converter. The heat dissipating fins and the DC--DC converters are arranged so that they are vertically disposed one over the other with respect to the main board.

Abstract: A data transmission control device for controlling the data transfer between two memory means on the basis of an instruction from a processor is disclosed in which the instruction from the processor is decoded, a transfer request is issued to each memory means a plurality of times, depending upon a transfer unit indicated by the decoded instruction and an access unit of each memory means, a data buffer is provided between the memory means to temporarily store data whichis transferred from one of the memory means to the other memory means, and the issue of a transfer request to each memory means is allowed or stopped in accordance with the quantity of data stored in the data buffer.