Technical data

SDA Description
607
608 30$: BNEQ 40$ ;If NEQ paper problem
609 ADDW3 #1,R1,UCB$W_BOFF(R5) ;Save number of characters remaining
610 DEVICELOCK -
611 LOCKADDR=UCB$L_DLCK(R5),- ;Lock device interrupts
612 SAVIPL=-(SP) ;Save current IPL
613 BITW #^X80,LP_CSR(R4) ;Is it ready now?
614 BNEQ 35$ ;If NEQ, yes, it’s ready
615 BISB #^X40,LP_CSR(R4) ;Set interrupt enable
616 WFIKPCH 40$,#12 ;Wait for ready interrupt
617 IOFORK ;Create a fork process
618 BRB 10$ ; ...and start next output
619
620 35$:
621 DEVICEUNLOCK -
622 LOCKADDR=UCB$L_DLCK(R5),- ;Unlock device interrupts
623 NEWIPL=(SP)+ ;Restore IPL
624 CLRW LP_CSR(R4) ;Disable device interrupts
625 BRB 10$ ;Go transfer more characters
626 ;
627 ; PRINTER HAS PAPER PROBLEM
628 ;
629
630 40$: CLRL UCB$L_LP_OFLCNT(R5) ;Clear offline counter
631 ADDW3 #1,R1,UCB$W_BOFF(R5) ;Save number of characters remaining
632 50$: CLRW LP_CSR(R4) ;Disable printer interrupt
633 IOFORK ;Lower to fork level
634 BBS #UCB$V_CANCEL,UCB$W_STS(R5),80$ ;If set, cancel I/O operation
635 TSTW LP_CSR(R4) ;Printer still have paper problem?
636 BLSS 55$ ;If LSS yes
637 MOVL #15,UCB$L_LP_TIMEOUT(R5) ;Set timeout value
638 BRB 10$ ; ...and start next output
10 Inducing a System Failure
If the operating system is not performing well and you want to create a dump
you can examine, you must induce a system failure. Occasionally, a device driver
or other user-written, kernel-mode code can cause the system to execute a loop of
code at a high priority, interfering with normal system operation. This can occur
even though you have set a breakpoint in the code if the loop is encountered
before the breakpoint. To gain control of the system in such circumstances, you
must cause the system to fail and then reboot it.
If the system has suspended all noticeable activity (if it is ‘‘hung’’), see the
examples of causing system failures in Section 10.2.
If you are generating a system crash in response to a system hang, be sure
to record the PC at the time of the system halt as well as the contents of the
general registers. Submit this information to Compaq, along with the Software
Performance Report (SPR) and a copy of the generated system dump file.
10.1 Meeting Crash Dump Requirements
The following requirements must be met before the system can write a complete
crash dump:
• You must not halt the system until the console dump messages have been
printed in their entirety and the memory contents have been written to the
crash dump file. Be sure to allow sufficient time for these events to take place
or make sure that all disk activity has stopped before using the console to
halt the system.
SDA–31