1. xerox 560 computer system - The UK Mirror Service
1. xerox 560 computer system - The UK Mirror Service
1. xerox 560 computer system - The UK Mirror Service
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
change the rate on the primary console to retain parallelcontrol. <strong>The</strong> alternate {local) device creates a log of allSCC transactions. <strong>The</strong> normal (log) output on I/O subchannelX'OB' is suspended for the duration of the SCCassignment to the remote channel (REMOTE CHANNELswitch in SCC position; ALTSEL switch in OFF position).CONTROL COMMANDSA set of commands and display formats implements operatorcommunication with hardware through the System ControlConsole. <strong>The</strong>se hardware-control commands, called II SCCFunctions ll , are independent, direct hardware controls asdistinguished from the software-level operating controlsactivated from the SCC through the normal I/o <strong>system</strong>. Aspecial micro-processor, working independently of theBP, senses and controls the execution of SCC functions.<strong>The</strong> flexibility of character-oriented communications equipmentand micro-programmed control significantly enhancemany <strong>system</strong> operating and diagnostic features.<strong>The</strong> basic command format provides a four-level interlockon critical <strong>system</strong> controls by requiring a correct fourcharactersequence to initiate a command action. In addition,context analysis is provided to assure that commandsare executed only in appropriate <strong>system</strong> states. Thisbasic format requires that each command is preceded by theIIcontrol-Z II character (control and Z keys depressed simultaneously).Note that within this text, the control-Z characteris represented wi th the symbol II ZCII .A typical command sequence is to enter IIZ C HLTII from theSCC. <strong>The</strong> <strong>system</strong> responds by printing II (HLT)II on the nextline of the SCC printout, and forcing the <strong>system</strong> to haltinstruction execution and enter the IDLE state. If a commandcannot be executed due to improper syntax or context,the <strong>system</strong> provides an odvisory message following the commandecho indicating the probable source of error. A typicalexample of the display format is II(RSY) *EVENT A1*1I,indicating that a reset command may not be executed priorto halting instruction execution. (Refer to Table 21 fora complete listing of event messages.)<strong>The</strong> various control functions that may be exercised fromthe SCC may be generally classified into three categories:operator control commands, diagnostic control commands,and maintenance control commands.OPERATOR CONTROL COMMANDS<strong>The</strong>se commands provide controls which an operator normallyuses to control the <strong>computer</strong> <strong>system</strong>. By enteri ng the appropriatecommand the operator may direct the <strong>computer</strong> <strong>system</strong>to load, run, halt, reset, read/set the sense switches, orissue a IIconsole interrupt ll to the operating software.<strong>The</strong> sense switch control and console interrupt commandsmay interact with the software and are always operative.All other SCC functions may be enabled or disabled bythe SCC FUNCTIONS switch on the SCPoTable 2<strong>1.</strong>Event MessagesDisplay*EVENT 00**EVENT AO**EVENT A1**EVENT A2**EVENT M**EVENT A8**EVENT FO**EVENT Fl**EVENT F4**EVENT F6**EVENT F9*SignificanceSystem Initialization; POWER ON or SUPER RESET.cImproper syntax for Z format command.Command not executed; Improper syntax or <strong>system</strong> may not be in IDLE mode.Command not executed; <strong>system</strong> not in maintenance mode.Command not executed; SCC FUNCTION switch is in DISABLE position.Power ride through; recoverable power line fai lure detected; power on trap requested.Trap requested occurred; inhibited in P-Mode.Basic processor error halt; watchdog timeout reset issued when watchdog timeout alarm bitset. (See II Processor Control Word ll .)Basic processor halt; Address Halt.Basic processor halt; Processor-Detected Fault (PDF).System failed micro-diagnostic test (followed by Single Clock Status Register display of theelement that fa i led).Control Commands 153