| 摘要 |
To make the data transfer in streaming mode as independent as possible of the length of the block gaps in magnetic tapes and the speed of the recording carrier, or in order to save unused revolution times in magnetic discs, in a sequence of several input/output commands of the machine programme controlling the streaming mode, at the beginning of such a sequence in each case two input/output commands are processed by the processor (CPU) without in the meantime waiting for a command execution acknowledgement (T-INT) by the input/output unit (IOP) and transferred as commands (SDV) to the input/output unit (IOP), the second command and possibly subsequent commands as a rule being temporarily stored so that one command is always provided in advance and after an input/output operation has been completed can be immediately forwarded to the recording device (PEx). Control by device lists (PE-LIST1) in the processor (CPU) for determining the commands within a sequence. Use of two different logic device addresses in alternating sequence for the same device (PEx) in order to avoid rejection of the command processing in the processor (CPU) and/or input/output unit (IOP) which are weighted as uniform device addresses (PE-AD) at the relevant processing level (e.g. IOP, CH or CE/PE). Manyfold possibilities of adaptation to given or predetermined sequence conditions within the data processing system. <IMAGE>
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