Abstract: In a data processing system in which data is transferred between memory areas through a transfer buffer shared by the memory areas, receive capability indication means which is commonly accessable by the memory areas and contains information indicating whether data can be transferred to the respective memory areas or not is provided, and data to be transferred from one memory area to other memory area is stored in the transfer buffer in accordance with the content of the receive capability indicator.

Abstract: An on-line system having a plurality of terminal equipments and host computers connectable to the terminal equipments, each host computer responsive to a job request from a terminal equipment being provided with an on-line process for transferring the control of the job request to a job execution process determined in accordance with the content of the job request, and a plurality of regular job execution processes for executing, if the job request is a regular job request, a regular job for the regular job request. The on-line control process is provided with an irregular job execution process space generating process for generating an irregular job execution process space for the irregular job execution.