File: PWRF.PA of Tape: Sources/RTS/s3
(Source file text)
/RTS-8 POWER FAIL RECOVERY TASK /THIS TASK IS EXECUTED WHEN POWER RETURNS AFTER A POWER FAILURE. IT /RESTORES THE CLOCK AND TELETYPE FLAGS ITSELF, BUT DEPENDS ON OTHER /RTS-8 HANDLERS TO PROVIDE A ROUTINE WHICH, WHEN CALLED, RE-INITIALIZES /THEIR DEVICE. /THE ACTION TO BE TAKEN ON POWER FAILURE IS DETERMINED BY THE /CONTENTS OF THE TABLE "PFLTBL", WHICH CONTAINS ONE WORD /PER TASK. A TASK MAY ALTER ITS WORD IN THIS TABLE BY SENDING A /MESSAGE TO THE POWER-FAIL TASK. THE FORMAT OF THE MESSAGE IS: /WORD 1 EVENT FLAG (RTS-8 PUTS TASK NUMBER IN LOW BITS) /WORDS 2-3 RESERVED FOR RTS-8 /WORD 4 NEW TABLE ENTRY VALUE /IF THE TABLE ENTRY VALUE IS 0, NOTHING WILL BE DONE FOR THE /CORRESPONDING TASK. IF THE VALUE IS 7777, THE TASK'S EVENT FLAG /WAIT BIT WILL BE CLEARED. IF THE VALUE IS BETWEEN 0 AND 7777, IT /IS CONSIDERED TO BE THE ADDRESS OF A SUBROUTINE IN THE TASK'S FIELD /TO WHICH THE TASK WILL BE DERAILED WITH ITS EVENT FLAG WAIT BIT CLEARED. TASK= PWRF CUR= 10 INIWT= 0 /INITIALIZATION CODE FIELD CUR%10 *200 START, STA PTR, CDF 0 CTR, TAD I (3 /GET POINTER TO POWER-FAIL EVENT FLAG PWFLEF, DCA PWFLEF /WHICH IS ONE LOC BEFORE POWER-UP ROUTINE TAD (4000+TASK DCA I PWFLEF /INITIALIZE IT TO "WAITING" PWFLLP, IOF /TESTING TWO THINGS - MUST HAVE IOF CDF 0 TAD I PWFLEF /HAS POWER GONE DOWN AND COME UP? SNA CLA JMP POWRUP /YES TAD I (TASK^2+MSGTBL SZA CLA /ANY MESSAGES FOR ME? JMP GETMSG /YES - GO READ MAIL CIF 0 CDF CUR /NOTHING TO DO - WAITM /WAIT FOR SOMETHING TO HAPPEN EORMWT JMP PWFLLP /ARISE, FAIR DAMSEL! GETMSG, ION CAL RECEIVE /GET PENDING MESSAGE MADDR, 0 DCA .+1 MEFPTR, MSGCDF, HLT /SET DF TO MESSAGE FIELD TAD MSGCDF DCA MEFCDF /SAVE CDF FOR POST CAL AC7775 TAD MADDR DCA MEFPTR /POINT TO MESSAGE EVENT FLAG TAD I MEFPTR /WHICH CONTAINS SENDING TASK NUMBER AND (177 /IN LOW ORDER 7 BITS TAD (PFLTBL DCA PTR TAD I MADDR /GET NEW TABLE ENTRY CDF CUR DCA I PTR /STORE IT TAD MEFPTR CAL POST /POST MESSAGE EVENT FLAG MEFCDF, 0 JMP PWFLLP /HERE ON POWER UP POWRUP, TAD (4000+TASK DCA I PWFLEF /RESET FLAG FOR NEXT POWER FAILURE CDF CUR ION /RESTORE INTERRUPTS /RESTORE CLOCK AND TELETYPE FLAGS AND INTERRUPT ENABLES IFDEF TTY <TLS> /ONLY SURE WAY TO SET TTY FLAG IFDEF OS8 <OSTTDV^10+6006> /DITTO FOR OS/8 TTY IFDEF CLOCK < TICKS= HERTZ%SHERTZ IFZERO CLKTYP <6131> /ENABLE CLOCK INTS FOR DK8EA,C IFZERO CLKTYP-4 <6103> /ENABLE CLOCK INTS FOR WVDMINTF IFNZRO CLKTYP&1 < /COMMON DK8EP, KW12 INIT CODE TICKS= 1750%SHERTZ IFZERO CLKTYP-3 < /SPECIFIC DK8EP INIT CODE CLZE= 6130 STA CLZE /ZERO COMMAND REGISTER ON DK8EP TAD (5311-4100 /5310 = ENABLE INTS, 1 KHZ, MODE 1 > CLLR= 6132 /CALLED CLDE ON DK8EP CLAB= 6133 TAD (4100 /4100 = 1 KHZ, MODE 1 CLLR /LOAD COMMAND REGISTER CLA /CLLR DOESN'T CLEAR AC TAD (-TICKS CLAB /SCALE DOWN CLOCK TO SOFTWARE RATE CLA /DOES NOT CLEAR AC > IFZERO CLKTYP-1 < /SPECIFIC KW12 INIT CODE CLEN= 6134 TAD (300 /FORCE CLOCK BUFFER INTO COUNTER AND CLEN /ENABLE KW12 INTERRUPTS CLA /THIS DOESN'T CLEAR AC EITHER > IFZERO CLKTYP-2 < /PDP8/A INIT CODE CLEN= 6135 CLA IAC CLEN /ENABLE CLOCK INTERRUPTS CLA /(JUST IN CASE) > > /END OF CLOCK CONDITIONAL CLA IAC DCA CTR /PERFORM TASK-DEPENDENT ACTIONS PWRUPL, TAD CTR TAD (PFLTBL DCA PTR TAD I PTR /GET CONTROL WORD FOR THIS TASK SNA JMP PWRUPN /NOTHING TO DO CMA SNA JMP PWRUPE /JUST CLEAR EVENT FLAG WAIT CMA DCA DRLADR TAD CTR CAL /DERAIL THE TASK DERAIL /INTO THE SUBROUTINE OF ITS CHOICE DRLADR, 0 PWRUPE, TAD CTR CAL UNBARG EFWT!EORMWT /CLEAR ALL FLAGS DEPENDING ON EFWT PWRUPN, TAD CTR TAD (-NTASKS SNA CLA /THROUGH? JMP PWFLLP /YES ISZ CTR JMP PWRUPL IFZERO NTASKS-40&4000 <PAGE> PFLTBL, ZBLOCK NTASKS+1 /FIRST WORD NOT USED IFDEF SIDK < *PFLTBL+SIDK -1 > IFDEF SDA < *PFLTBL+SDA 0 /WILL BE SET BY SDA > IFDEF DTA < *PFLTBL+DTA -1 > IFDEF RK8 < *PFLTBL+RK8 -1 > IFDEF RF08 < *PFLTBL+RF08 -1 > IFDEF DF32 < *PFLTBL+DF32 -1 > IFDEF LPT < *PFLTBL+LPT -1 > PAGE $-$-$