IBM SY31-0207-1 Field Engineering 5410 Processing Unit Theory of Operation free download

File name SY31-0207-1_Field_Engineering_5410_Processing_Unit_Theory_of_Operation.pdf

Field Engineering Theory of Operation Processing Unit SY31-0207-1 Identifier (units) TENS UNITS - Identifier BitO Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 Tens Reserved IndA Ind B Ind C IndO Ind E Ind F IndO Units Reserved IndA Ind B Ind C Ind D Ind E Ind F IndO Figure 6-7. Message Display Unit Power On/Off Switch Stop Key/Light This switch initiates the power on/off sequence of the This key is pressed to cause a processor stop. system. A system reset is performed as part of the power on/off sequence. Main storage data may be lost when power The processor is stopped at the end of the operation in pro is dropped. gress when the key was pressed. I/O data transfers are com pleted without loss of information. Processor stop turns on the stop light. Program Load Key The processor may be restarted without loss of information This key is pressed to start initial program loading from the by depressing the start key. MFCU or Disk file. The I/O device is selected with the program load selector switch. A system reset is performed as part of the program load sequence. Start Key Pressing the program load key allows the first card or record This key is pressed to start or continue operation. from the MFCU or Disk File to be read and stored in main storage, beginning at location 0000. When the key is re Pressing the start key turns off the stop light and allows the leased, the CPU proceeds to execute the instruction sequence processor to continue its normal operation. starting at location 0000. Normal program load from the MFCU is executed through the primary hopper. The start key is also used, in conjunction with the CE modes of operation, to start and/or advance the processor clock. Should the I/O device selected be not ready, the console I/O attention light will come on when the program load On systems without the dual program feature, pressing the key is pressed. Normally, to complete the program load start key clears the message display unit and allows the pro