.TITLE DX11
.SBTTL DX11 INTERRUPT ROUTINE - DATA AREAS AND DEFINTIONS
;DX11 INTERRUPT ROUTINE
;DATE: 03-FEBRUARY-84
;NOW READ SYSTEM CONFIGURATION FILE CONFIG PAL11
./ COPY=CONFIG
DX11BITS=1
DX11PAR=1
.PARAM=1
DEVPAR=1
EMTNAM=1
;
./ COPY=SYSMAC
.GLOBL $DX11I,DXTT,DXTTP,DXSPWT,DX11PCB,DXPROC,DXINIT,DXOPEN
.GLOBL DXTRAN,DXSTPR,DXBAST,DXBSTB,DXBSTA,$V,$SAVE,$RESTORE
;
DXMAX1=132. ;BURST LENGTH FOR LONG BURST DEVICES
; DXMAX2=4 ;BURST LENGTH FOR TERMINALS
; DXLONG=X'60 ;FENCE FOR LONG BURST
; DXDEV1 - LOWEST ADDRESS SUPPORTED
; DXDEV2 - ONE MORE THAN HIGHEST ADDRESS SUPPORTED
.GLOBL DXDEV1,DXDEV2
;
; DXDEV1 AND DXDEV2 MUST BE SET CORRECTLY TO MATCH THE ADDRESS RANGE
; RECOGNISED BY THE DX11 HARDWARE
;
DXSPWD=1;SPW M.S BYTE - DST OFFSET
DXSPWS=0;SPW L.S BYTE IS IMMEDIATE STATUS
;
; BITS FOR XDFLAG
XXOFFF=20 ;OFFLINE BASE -DETACH DEV WHEN IDLE
XXSTAF=40 ;STATUS MAY BE RELEASED
XXDATF=100 ;DATA TRANSFER REQUEST NOT STATUS REQUEST
XXCHNF=200 ;DEVICE HAS TRANSFER OR STATUS IN PROGRESS
; BITS FOR XXSTAT
XXRDY=200 ;DEVICE IS FULLY READY - THIS MUST BE SIGN BIT
XXRDYF=100 ;DEVICE BECOMING READY
XXCMDF=40 ;PROCESSING NON-IMMEDIATE COMMANDS
XXSTKS=10 ;STATUS IS STACKED
XXNSTA=4 ;E.S. OUTSTANDING ;SET ON NON-IMMED CMD,
;CLEAR TO PRESENT STATUS
XXABOR=2 ;DO NOT DO DATA TRANSFERS
XXRSTF=1 ;DO NOT PRESENT ES
;
; DX11 PROCESS CONTROL BLOCK
;
.IFDF USERMODE
PROCMODE=UMODE
.IFF
PROCMODE=KMODE
.ENDC
STKSZE=100
DX11PCB:0,0,0
DXPROC,PROCMODE ;ENTRY POINT,PSW
DX11STK+<STKSZE*2>
DX11DB
0,0,0,0,0,0 ;REGISTER STORAGE
0 ;MMU ADDRESS REGISTER STORAGE
DX11STK:.=.+2*STKSZE
;
DX11DB:;DX11 BASE AREA
DXTTP: 0 ;TUMBLE TABLE SOFTWARE POINTER
DXQ1: 0
DXCHN2: 0 ;SECONDARY CHAIN USED FOR HOLD
DXCBSY: 0 ;HOLDS CUBSY TO RESET AFTER IR IF ALL DEV FINISHED RESETING
DXBYTE: 0 ;FOR READING ODD BYTE (NB FULLWORD)
DXCNTX: 0 ;COUNT OF DEV NOT FINISHED RESETING
;
;OFFLINE DEVICE QUEUES
;
XXSCNT: .BYTE 0 ;CNT OF DEV WITH PENDING OFFLINE SENSE
XXSCNS: .BYTE 0 ;COUNT OF DEV WITH PENDING OFFLINE SENSE AND HIO
XXSNQ2: .BYTE 0 ;CHAIN OF OFFLINE DEVICES WITH SENSE AND HIO
XXSNQ3: .BYTE 0 ;QUEUE FOR INITIALISING OFFLINE STATUS
XXSCN3: .BYTE 0 ;NUMBER OF ITEMS OM DXSNQ3
.EVEN
;
DXIRSW: 0 ;INTERRUPT SWITCH
DXSEM: 0,0 ;SEMAPHORE USED BY INTERRUPT ROUTINE AND DX11 PROCESS
;
; OFFLINE DEVICE BASE
DXBAS1: .=.+DXXBLN
DXBEND:
.=DXBAS1+XNSNS
1 ;ONE SENSE BYTE ONLY FOR OFFLINE DEVICES
.=DXBEND
;
; ONLINE BASE ADDRESS TABLE
DXBSTA: .=.+2*<DXDEV2-DXDEV1>
DXBSTB:
DXBAST=DXBSTA-<2*DXDEV1>
;
.PAGE
.SBTTL DX11 PROCESS CODE
DXPROC: ;FIRST ENTRY TO DX PROCESS
JSR R5,DXNITT ;QUEUE OFFLINE INITIALISING STATUSES
BIC #CUBSY,@#DXCS ;CLEAR CUBSY UNLESS LOCKO SET EARLIER
BIS #INTEN,@#DXCS ;ENABLE DX11 INTERRUPTS FOR FIRST TIME
BR DXNEXT
;
;REMOVE INACTIVE DEVICE BASE FROM CHAIN
;
DXAB01: BNE DXER20 ;INVALID LENGTH
DXABOR: JSR R5,TRANOK ;TERMINATE DATA TRANSFER
DXNST:
MOV #DXQ1,R0 ;UNCHAIN BASE PROVISIONALLY
JSR R5,$UCHAIN ;UNCHAIN HEAD FROM QUEUE
BIC #XXCHNF,-(R1) ;MARK NOT CHAINED
BEQ DXIIII ;EXIT IF NOTHING TO DO
MOV R1,R4
SUB #XDFLAG,R4 ;GET BASE POINTER
CMP #XXOFFF,(R1) ;CHECK IF OFFLINE ACTION ONLY
BEQ 1$
JSR R5,DXTR01 ;OR RECHAIN IF NEDDED
BR DXIIII
1$: JSR R5,DXSB2 ;DISCONNECT THIS DEIVCE FROM OFFLINE BAS
BR DXIIII
DXER20: TRAP 7 ;INVALID DATA LENGTH
DXNST1: BR DXNST
;
;GO TO SLEEP AFTER RE-ENABLING DX11 INTERRUPTS
;
DXSLEEP:
BIS #INTEN,@#DXCS ;ENABLE DX11 INTERRUPTS
MOV #DXSEM,-(SP)
EMT P ;WAIT FOR IR TO SAY SOMETHING TO DO
DXNEXT:
MOV #DXSLEEP,-(SP) ;SET LINK
BIC #INTEN,@#DXCS ;DISABLE DX11 INTERRUPTS
;
;DEAL WITH FIRST ITEM ON DX11 WORK QUEUE
;MUST BE OBEYED DISABLED FOR DX11 INTERRUPTS
DXIII:
TST DXCBSY ;IF AFTER SYS OR SEL RST AND CNT EXHAUST
BNE 1$ ;RESET INTERRUPT ROUTINE AND CUBSY
TSTB DXCNTX
BNE 1$
JSR R5,DXRSR ;GO TIDY UP
1$:
DXIIII: BIT #DONE!GO,@#DXCS ;DON'T START ACTION IF ACTIVE (DXCB NOT
;PROTECTED BY LOCKO
BNE DXXIT ;(DONE SET PH 4 BEFORE GO RESET IN PH 7
MOV DXQ1,R4 ;LOOK FOR WORK ON MAIN QUEUE
BEQ DXXIT ;B IF QUEUE EMPTY
BIT #XXDATF,-(R4) ;TEST IF DATA TRANSFER WANTED
BEQ DXST ;LOOK FOR STATUS OTHERWISE
SUB #XDFLAG,R4
BITB #XXCMDF,XXSTAT(R4);ERR IF DATA WHEN NOT IN CMD
BEQ DXER22
BITB #XXABOR,XXSTAT(R4);MARKED TO ABORT?
BNE DXABOR ;B IF ABORTING
TSTB DXCNTX
BNE DXHOLD ;TO HOLD WORK IF ANY DEV NOT FINISHED RESETING
;
MOV #-DXMAX1,R0
;
; MOV (PC)+,R0 ;SET COMPLEMENTS OF BOTH BURST LENGTHS
; .BYTE -DXMAX1,-DXMAX2 ;LONG SHORT
; CMPB XDADDR(R4),#DXLONG
; BLO 3$
; SWAB R0
;3$: MOVB R0,R0 ;CLEAN LENGTH
CMP R0,XDLEN(R4) ;COMPARE WITH MAX ALLOWED
BGT 4$ ;B IF GREATER THAN MAX
MOV XDLEN(R4),R0 ;IF LT MAX USE IT
BPL DXAB01 ;EXIT IF COUNT EXHAUSTED
4$:
MOV #SWDATA,DXIRSW ;MARK DATA EXPECTED NEXT
.IFNDF MMU
MOV XDDATA(R4),@#DXBA ;SET BUS ADDRESS
MOV #FCTN2,R1 ;PREPARE FOR OUTPUT TO CHANNEL
.ENDC
.IFDF MMU
MOV R2,-(SP)
MOV R0,-(SP)
CLR R0
MOV XDDATA(R4),R2 ;PICK UP VIRTUAL ADDRESS
CMP R2,#VSTART ;IS ADDRESS REAL
BLO 10$ ;B IF NO EXTENDED ADDRESS
MOV XXAR(R4),R1 ;PICK UP PAGE ADDRESS REGISTER
ASHC #6,R0 ;CONVERT BLOCK NUMBER TO ADDR
BIC #160000,R2 ;EXTRACT OFFSET FROM VIRT ADDR
ADD R1,R2
ADC R0 ;FORM 18BIT ADDRESS IN R1,R0
BEQ 10$
TRAP 7
;EXTENDED ADDRESS BITS MUST BE ZERO
; ASH #3,R0 ;SHIFT BITS 16 AND 17 FOR CSR
10$: MOV R2,@#DXBA ;SET BOTTOM 16BITS OF ADDRESS
MOV #FCTN2,R1
; MOV R0,R2 ;SAVE EXTENDED ADDRESS BITS
MOV (SP)+,R0 ;RESTORE BYTE COUNT
.ENDC
BITB #1,XXCMD(R4) ;CHECK FOR INPUT OR OUTPUT
BEQ 5$
ASR R1 ;SET INPUT FROM CHANNEL
BIT #1,XDDATA(R4)
BEQ 5$ ;EVEN ADDRESS IS SIMPLE
MOV #-1,R0 ;SET UP SPECIAL READ
MOV #SWDATX,DXIRSW
MOV #DXBYTE,@#DXBA
5$: MOV R0,@#DXBC ;SET BYTE COUNT IN DX11
SUB R0,XDLEN(R4) ;SET LENGTH AND ADDRESS AS IF
SUB R0,XDDATA(R4) ;TRANSFER HAD COMPLETED SUCESS
.IFDF MMU
; BIS R2,R1 ;INSERT NEW EXTENDED ADDRESS
;EXTENDED ADDRESS BITS MUST BE ZERO
MOV (SP)+,R2
; BIC #36,@#DXCS ;CLEAR OLD EXTENDED ADDRESS BITS
.ENDC
BIS R1,@#DXCS ;SET FUNCTION (READ/WRITE)
DXST3:
MOVB XDADDR(R4),@#DXCUAR ;SET DEVICE ADDRESS IN DX11
INC @#DXCS ;SET GO FOR DX11
DXXIT:
RTS PC ;TO SLEEP IF PROCESS,EXIT IF IR
;
DXER22: TRAP 7 ;ATTEMPT TO START DATA TRANSFER WITH NO COMMAND
;
;DEVICE HAS NO DATA OUTSTANDING - CHECK FOR STATUS
;PRO TEM NO SPECIAL ACTION IF SECONDARY STATUS ***BEWARE****
DXST:
BIT #XXSTAF,(R4)+
BEQ DXNST1 ;UNCHAIN DEVICE IF NO STATUS WANTED
SUB #XCHAIN,R4
BITB #XXRSTF,XXSTAT(R4)
BEQ DXST10 ;B UNLESS HAD RESET
JSR R5,STPRST ;TIDY UP DEVICE
DXIIJ1:
BR DXIIII ;GET NEXT ITEM ON WORK QUEUE
;
; PLACE WORK ON HOLD QUEUE WHILST AWAITING TERMINATION OF SEL RST
DXHOLD:
MOV #DXQ1,R0
JSR R5,$UCHAIN
MOV #DXCHN2,R0
JSR R5,$CHAIN
BR DXIIJ1 ;TO PROCESS NEXT ITEM OF WORK
;
; NORMAL STATUS PROCESSING
;
DXST10:
TSTB DXCNTX ;SHOULD WE TEST DXCBSY
BNE DXHOLD;TO HOLD ANY WORK UNTIL ALL DEV FINISHED RESET
MOVB XSTATUS(R4),@#DXCUSR;SET STATUS FROM DEVICE BASE
BICB #XXABOR,XXSTAT(R4);CLEAR ABORT FLAG
BPL 1$ ;B IF PRESENTING INITIALISING STATUS
BITB #XXCMDF,XXSTAT(R4);SEE IF PROCESSING CMD STATE
BEQ DXER21 ;ERR IF PRESENTING END STATUS WITH NO CMD
1$:
MOV #SWSTAT,DXIRSW ;MARK ESEND EXPECTED NEXT
BIS #STKSTA!FCTN3,@#DXCS;SET SUPRESSIBLE STATUS PROVISIONALL
BITB #CHEND,XSTATUS(R4) ;NEVER CHANNEL END WITHOUT DEVICE END
BEQ DXST3 ;B IF SUPPRESSIBLE-I.E. NOT PRESENTING CE OR DE
BITB #XXSTKS,XXSTAT(R4);HAS IT ALREADY BEEN STACKED
BNE DXST3 ;B IF ALEADY STACKED
BIC #STKSTA,@#DXCS ;NOT SUPPRESSIBLE
BR DXST3 ;B TO SET DEV ADDR AND GO
;
DXER21: TRAP 7
;
.PAGE
.SBTTL DX11 INTERRUPT ROUTINE -INTERRUPT CODE
;REGISTER USASE
;R0 - WORK REGISTER
;R1 - WORK REGISTER
;R2 - POINTER TO CURRENT TUMBLE TABLE ENTRY
;R3 - FIRST WORD OF TUMBLE TABLE ENTRY
;R4 - BASE (SCA)
;R5 - LINK REGISTER
;
;
;
; SPECIAL SYSTEM RESET INTERRUPT ROUTINE
; SYSTEM RESET HAS BEEN DETECTED IN THE MAIN IR WHICH HAS SWITCHED
; THE INTERRUPT VECTOR TO HERE AS THERE MAY BE MORE SYSTEM RESETS
; (BUT ONLY SYSTEM RESETS) AND WE MAY HAVE TO DEAL WITH THEM
; QUICKLY - E.G 370 HDM
;
DXIR1: BIC #DONE,@#DXCS
MOV R2,-(SP)
MOV DXTTP,R2;PICK UP ADDRESS OF CURRENT TUMBLE TABLE ENTRY
BR DXIR12
DXIR11: CLR (R2)+;CLEAR ENTRY(CAN ONLY BE ANOTHER SYSRT AS CUBSY SET
TST (R2)+ ;SKIP ADDRESS AND COMMAND
BIT #DXTTL-1,R2 ;CHECK FOR WRAP
BNE DXIR12 ;OVERFLOW HAS NOT OCCURED
MOV #DXTT,R2 ;BACK TO BEGINNING OF TABLE
DXIR12: TST (R2) ;IF NULL ENTRY THEN ALL PROCESSED
BNE DXIR11 ;CONTINUE
MOV R2,DXTTP ;SAVE CURRENT TUMBLE TABLE POINTER
MOV (SP)+,R2
RTI
;
; MAIN INTERRUPT ROUTINE
;
; MAIN TUMBLE TABLE SCAN LOOP
;
DXER3: TRAP 7
$DX11I: JSR R5,$SAVE ;SAVE REGISTERS
MOV DXTTP,R2 ;SET UP TUMBLE TABLE POINTER
BIC #DONE,@#DXCS ;CLEAR DONE TO PERMIT FURTHER INTERRUPTS
DXIMOR: MOV (R2),R3 ;GET FIRST WORD OF ENTRY
BNE DXINXT ;BRANCH IF USED
; NOW HAVE COME TO END OF TT PROCESSING
DXINON: SUB DXTTP,R2 ;FIND NUMBER OF ENTRIES PROCESSED
CMP R2,#DXTTL ;COMPARE WITH TABLE LENGTH
BGE DXER3 ;ERROR IF FULL TT DONE - OVERFLOW?
ADD R2,DXTTP ;SAVE NEXT TT SLOT ADDRESS
BIC DXCBSY,@#DXCS;CLEAR CUBSY IF NO RESET OUTSTANDING
JSR PC,DXIII ;*** RESTART TOP ENTRY ON Q
;
DXIXIT: JSR PC,$RESTORE ;RESTORE REGISTERS
RTI
;
;
DXINXT: CLR (R2)+ ;MARK ENTRY AS NOT IN USE (BIT EARLY)
CLR R0
BISB (R2),R0;DEVICE ADDRESS FROM TT
TST (R2)+ ;SKIP PAST SECOND WORD
MOV DXIRSW,R1 ;SAVE INTERRUPT SWITCH
MOV #SWNORM,DXIRSW ;RESET TO NORMAL
ASL R0 ;DEVICE ADDRESS*2
MOV DXBAST(R0),R4 ;PICK UP SCA ADDRESS
JSR R5,(R1) ;PROCESS TT ENTRY
BIT R2,#DXTTL-1 ;CHECK FOR WRAPAROUND
BNE DXIMOR
MOV #DXTT,R2
BR DXIMOR
;
; INDIVIDUAL TUMBLE TABLE ENTRIES
;
;SUBROUTINE TO REMOVE DEVICE R0 FROM OFFLINE CHAIN
DXISC0: ASR R0 ;SPECIAL ENTRY SHIFTING R0 ONE PLACE
DXISC: MOV (R5)+,R1;SEARCH AND REMOVE ITEM FROM OFFLINE CHAIN
SUB #DXSPWT+DXSPWD,R1;GET ADDRESS OF CHAIN HEAD
MOV @(R5)+,-(SP)
BEQ 33$;B IF CHAIN EMPTY
BR 32$ ;CHAIN NOT EMPTY
;
31$: DECB (SP) ;COUNT DOWN CHAIN
BEQ 33$ ;B IF REACHED END OF CHAIN
MOVB DXSPWT+DXSPWD(R1),R1 ;ON TO NEXT ON CHAIN
BIC #177400,R1
ASL R1
32$: CMPB R0,DXSPWT+DXSPWD(R1) ; CHECK IF FOUND
BNE 31$ ;B IF NOT FOUND
ASL R0
MOVB DXSPWT+DXSPWD(R0),DXSPWT+DXSPWD(R1);REMOVE FROM CHAIN
DECB @-2(R5) ;ADJUST COUNT OF ITEMS ON CHAIN
ASR R0
33$: TSTB (SP)+ ;POP STACK AND SET CC
RTS R5
;DEAL WITH SEL RST AND HIO FOR OFFLINE DEVICES WITH SENSE,R0=2(DEV ADDR)
;NOTE DEV NOT AT HEAD OF MAIN CHAIN AS IS PSEUDO-OPEN
;HENCE 'OWNS' THE SPECIAL BASE
DXIOSH: JSR R5,DXISC0 ;SHIFT R0 RIGHT,SEARCH AND IF FOUND ,REMOVE
XDADDR,XXSCNT ;MAIN CHAIN
BNE 1$ ;B IF OUND ON MAIN CHAIN
BIT #SELRST,R3
BEQ 2$ ;IF HIO ONLY THEN IGNORE IF ON 2ND OR 3RD CHAIN
JSR R5,DXISC
XXSNQ2,XXSCNS ;CHAIN OF HIO'D DEVICES
RTS R5
;FOUND ON FIRST QUEUE
1$: BIT #SELRST,R3
BNE 2$ ;FORGET IT IF SEL RST
ASL R0 ;2 (DEV ADDR)
MOVB XXSNQ2,DXSPWT+DXSPWD(R0);ELSE Q TO HEAD 2ND Q
;TO PRESENT ENDING STATUS ONLY
ASR R0
MOVB R0,XXSNQ2
INCB XXSCNS
2$:
SWXIT: RTS R5
;
.PAGE
.SBTTL NORMAL TT ENTRY PROCESSING
SWNOR1: TST R4 ;RECONSTRUCT CONDITION CODE
SWNORM: BNE NDATA0 ;B IF ONLINE DEVICE
OFFDE1: BIT #SYSRST,R3;ADDRESS OF DEV IMMATERIAL IF SYS RESET
BNE ERR01 ;BRANCH IF SYSTEM RESET
BIT #SELRST!INFDSC,R3
BNE DXIOSH ;B IF SEL RST OR HIO FOR OFFLINE DEV
BIT #UCHKS,R3;IF DEV NOT OPEN SHOULD HAVE SENT UC
BNE SWXIT ;IGNORE UNIT CHECKS SENT FOR OFFLINE DEVICES
BIT #TTMSK-CHIS+STKSTB,R3;OFFLINE DEV ALLOWED SENSE
BNE 1$ ;ERROR IF NOT CHIS FOR OFFLINE DEV
JMP DXISPS ;GO AND TRY SENSE
1$: TRAP 7 ;IMPOSSIBLE OFFLINE TT ENTRY
; DATA TRANSFER OUTSTANDING - CHECK FOR CUIS
SWDATX: TST @#DXBC ;ADJUST FOR ODD BYTE
BNE SWDATA ;NOTHING TO DO IF NO TRANSFER
MOV DXQ1,R1
TST -(R1) ;SKIP OVER XDFLAG *** NOT IN CAMBRIDGE CODE
MOV -(R1),R1 ;REAL DATA ADDRESS
MOVB DXBYTE,-(R1) ;*** COPY BYTE
SWDATA: MOV DXQ1,R1 ;GET ASSOCIATED DEVICE
TST -(R1)
ADD @#DXBC,-(R1) ;ALLOW FOR UNDONE PART OF TRANSFER
ADD @#DXBC,-(R1)
SUB #XDLEN,R1 ;GET BASE POINTER
CMP R1,R4 ;DOES TT ENTRY RELATE TO REQUEST
BNE SWNOR1 ;NO - TREAT AS UNSOLICITED
BIT #TTMSK-CHDEND-CUDEND,R3
BNE SWDAT0
BIT #CUDEND,R3
BEQ CHD00 ;DEAL WITH (NON-ERROR) CHDEND
TST XDLEN(R1) ;TEST IF TRANSFER COMPLETE
BMI SWXIT
JMP TRANOK ;REPORT COMPLETION
;
;CHDEND WITHOUT ERRORS
CHD00: MOV #XDCHD,R1 ;PREPARE TO REPORT CHANNEL TERMINATED DATA
JMP DXISE1
; DATA TRANSFER REQUESTED - NOT CUIS OR ERRORS
SWDAT0: BIT #CHIS+RESETS,R3 ;IS THIS UNRELATED TO DATA TRANSFER
BNE NDATA
; PARER OR NXM IN DATA
BIT #PARER!NXM,R3
BEQ 2$ ;NO
BISB #UC,XSTATUS(R4) ;SET UNIT CHECK IN STATUS
JSR R5,SETSN1 ;SET EQUCHK OR BUSOCK AS APPROPIATE
MOV #XDERR,R1 ;*** USE OF R1
JMP DXISE1 ;AND CALL ERROR ROUTINE
;
2$: TRAP 7 ;DX11 ERROR
;
OFFDEV: BR OFFDE1
ERR01: BR ERR00
;
; CHANNEL INITIATED SEQUENCE FOR ONLINE DEVICE
; CHIS + ESEND NOT PROPERLY HANDLED
NDATA0: BIT #CHIS+RESETS,R3
BEQ DXER63 ;IMPOSSIBLE SPONTANEOUS VALUE
NDATA: BIT #TTMSK+STKSTB-CHIS-CHENDS-ESEND,R3
BNE ERR00 ;BRANCH IF ERRORS STACKED STATUS ETC.
; HERE ON NON-REJECTED CHIS - I.E. CHIS WITH OPTIONALLY CHENDS
; NOTE SENSE FOR OFFLINE DEVICES IS FILTERED OFF EARLIER
MOVB -1(R2),R1 ;GET COMMAND CODE
BEQ SWXIT ;IGNORE TIO (INCLUDING PENDING STATUS CASES
BITB #XXCMDF!XXRSTF,XXSTAT(R4) ;ALREADY PROCESSING COMMAND
;OR CMD REC DURING SEL RESET
BNE DXICHK ;BRANCH IF SO
BITB #XXRDY!XXRDYF,XXSTAT(R4);SEE IF DEVICE READY OR GOING RE
BMI 1$;BRANCH IF PROPERLY READY
BEQ DXER61 ;ERROR OTHERWISE
BIC #XXSTAF,XDFLAG(R4);CANCEL STATUS REQUEST
BISB #XXRDY,XXSTAT(R4);MARK PROPERLY READY IF ACCEPTED CMD
1$:
BIT #CHENDS,R3 ;BRANCH IF IMMEDIATE COMMAND
BNE SWXIT
MOVB R1,XXCMD(R4) ;COMMAND TO DEVICE BASE (SCA)
MOVB #CHEND!DEVEND,XSTATUS(R4);PRESET NORMAL ENDING STATUS
BISB #XXCMDF!XXNSTA,XXSTAT(R4);MARK CMD PRESENT,ES OUTSTANDING
CMPB #SENSE,XXCMD(R4);IS IT A SENSE COMMAND
BEQ DXISNS
CLR XSENSE(R4) ;AS NOT IMMED CLEAR SENSE BYTES
CLR XSENSE+2(R4)
CLRB XCOUNT(R4) ;SET IN POS RANGE DURING COMMAND
MOV @XJUMP(R4),PC ;***** INFORM DEVICE OF COMMAND
;RETURN TO TT SCAN
;ASSUMES COMMAND IS FIRST ENTRY IN TABLE
; SENSE FOR OPEN DEVICES
DXISNS:
MOV XJUMP(R4),XJCOPY(R4) :***SAVE REAL JUMP TABLE
MOV #DXSNSJ,XJUMP(R4) ;SET UP SENSE DATA REQUEST
JMP DXSENS
;
;COMMAND RECEIVED DURING EARLIER COMMAND OR DURING SEL RESET
DXER61: TRAP 7;DEVICE NOT READY OR GOING READY
DXICHK: TRAP 7
;
; STATUS REQUEST OUTSTANDING
SWSTER: TRAP 7
;
SWSTAT: BEQ OFFDEV ;NOT OURS IF OFFLINE DEVICE
BIT #TTMSK+CMDREJ-ESEND-UCHKS-CHENDS-BSYS,R3
BNE NDATA0 ;NOT OURS IF CHANNEL INITIATED (CHIS +ESEND)
MOV DXQ1,R1
SUB #XCHAIN,R1
CMP R1,R4 ;CHECK CORRECT DEVICE
BNE SWSTER ;FAULT IF NOT
DXIES1: BIT #ESEND,R3 ;IS STATUS STACKED
BNE 2$
TSTB XXSTAT(R4)
BMI 1$;B UNLESS DOING INITIALISING STATUS PRESENTATION
BITB #XXSTKS,XXSTAT(R4) ;IF STATUS WAS SUPPRESSIBLE
BNE 2$ ;THEN TREAT AS STATUS ACCEPTED
1$:
BISB #XXSTKS,XXSTAT(R4);MARK STATUS STACKED -NOW SUPPRESSIBLE
RTS R5 ;RETURN TO TT SCAN
2$:
; TREAT STATUS WITHOUT DEVICE END AS SPECIAL ****************
;
; CMPB #CE,XSTATUS(R4) ;CHECK FOR CHANNEL END
; BEQ 3$ ;B IF STATUS TO BE PRESENTED AGAIN
;
BICB #XXCMDF!XXSTKS,XXSTAT(R4);CLEAR CURRENT CMD MARKERS
BISB #XXRDY,XXSTAT(R4) ;SET READY IN CASE GOING READY
CLRB XXCMD(R4) ;CLEAR OUTSTANDING COMMAND
3$:
BIC #XXSTAF,XDFLAG(R4) ;RESET STATUS REQUEST
RTS R5
;
DXER63: TRAP 7 ;ENDING STATUS ACCEPTED FOR DEV NOT PRESENTING STATUS
;
STKTIO: TSTB -1(R2) ;COMMAND RECEIVED WHILE ACTIVE
BNE NOTTIO ;FAULT IF NOT TIO
BITB #XXSTKS,XXSTAT(R4)
BNE DXIES1 ;TIO IS POSSIBLE ONLY IF STATUS IS STACKED
NOTTIO: TRAP 7
;
.PAGE
.SBTTL RESETS OR ERRORS
ERR00: BIT #RESETS,R3
BNE DXIF11 ;BRANCH IF SYSRST SELRST OR HIO
; CHIS WITH ONE OF PARER,BSYS,UCHKS OR STKSTB PRESENT
; OR ELSE NONSENSE TT ENTRY WITH ONE OF ESEND,CUDEND,CHDEND,NXM PRESENT
BIT #STKSTB!UCHKS!BSYS,R3
BEQ DXER63 ;NONSENSE ENTRY
BIT #RESETS+ESEND+CUDEND+CHDEND+NXM+CMDCHN,R3
BNE DXER63
BITB #XXCMDF,XXSTAT(R4) ;CHECK NO COMMAND PRESENT
BNE STKTIO
TSTB XXSTAT(R4)
BMI 4$ ;SKIP IF PROPERLY READY
BIC #XXSTAF,XDFLAG(R4) ;OR FORCE READY
BISB #XXRDY,XXSTAT(R4)
4$: BIT #STKSTB,R3
BNE DXISTI ;STACKED INITIAL STATUS
;WE HAVE CHIS + (UCHKS OR BSYS) - ASSUME UCHKS AND COMPLETE SENSE VALUE
; INTREQ IF SPW NON-ZERO
; BUSOCK IF PARER (BAD COMD PARITY)
; EQC IF NXM (BAD DST POINTER)
; CMDREJ OTHERWISE (UC IN DST)
MOV #INTREQ,R1
TSTB DXSPWT+DXSPWS(R0)
BNE SETSEN ;SET INTERVENTION REQUIRED AS ASSUME TRYING TO CLS
MOV #CMDRJ,R1
BIT #PARER!NXM,R3
BEQ SETSEN ;TO SET CMD REJECT IF NOT HARDWARE ERROR
SETSN1: MOV #EQUCHK,R1
BIT #NXM,R3
BNE SETSEN ;SET EQUIPMENT CHECK IF NXM
MOV #BUSOCK,R1
SETSEN: BISB R1,XSENSE(R4)
RTS R5
;
; STACKED INITIAL STATUS
DXISTI: MOV DXSPWT(R0),R1 ;RECONSTRUCT STATUS FROM SPW
MOVB R1,XSTATUS(R4)
BNE 1$
BISB -1(R2),R1 ;INSERT COMMAND NUMBER
MOVB (R1),XSTATUS(R4)
1$: BISB #XXRDY!XXRDYF!XXCMDF!XXSTKS,XXSTAT(R4);CMD PRESENT,STK ST
JMP DXSTP1 ;PRESENT STATUS - RETURN TO TT SCAN
;
DXER03: TRAP 7;POTENTIAL TT OVERRUN AT START OF SYS RESET PROCESSING
;
; HIO,SYSTEM OR SELECTIVE RESET - R0 = 2(DEVICE ADDRESS)
DXIF11:BIT #SYSRST,R3
BEQ DXIF12 ;B UNLESS SYSTEM RESET
;SYSTEM RESET HERE - HARDWARE HAS SET CUBSY
; CHECK NO TT OVERRUN YET AND SAVE CURRENT TT POINTER
SUB DXTTP,R2 ;ENTRIES PROCESSED
CMP R2,#DXTTL
BGE DXER03 ;ERROR IF POTENTIAL OVERRUN
ADD R2,DXTTP ;SAVE NEXT TT SLOT ADDRESS
BIT #DXTTL-1,DXTTP ;DID IT OVERRUN
BNE 0$
MOV #DXTT,DXTTP ;YES CORRECT POINTER
0$: MOV #DXIR1,@#DXI;SWITCH INTERRUPT ROUTINE IN CASE MORE INT
SUB #40,@#PSW;ALLOW DX INTS (CAN ONLY BE SY RST AS CUBSY SET
; CARRY ON SYSTEM RESET PROCESSING
CLRB XXSCNS ;RESET ALL OFFLINE DEVICES
CLRB XXSCN3
TSTB XXSCNT
BEQ 1$
MOVB #1,XXSCNT ;EXCEPT POSSIBLE CONNECTED DEVICE
1$: INCB DXCNTX ;PREVENT RELEASE OF CUBSY
CLR DXCBSY ;PRIME PROCESS TO RESET IR
MOV #DXCHN2,R1 ;RECHAIN EVERYTHING ON SECONDARY
MOV #DXQ1,R0 ;CHAIN TO MAIN CHAIN
JSR R5,$RECHN
MOV #DXBSTB,R5 ;SET TOP OF BASE TABLE
2$: MOV -(R5),R4 ;GET DEVICE BASE ADDRESS
BEQ 3$ ;LOOP IF THIS DEVICE NOT OPEN
JSR R5,DXISEX ;PROCESS AS FOR SELRST
3$: CMP R5,#DXBSTA ;DOWN TO LAST ENTRY
BHI 2$ ;LOOP IF NOT
;SIMULATE NORMAL INTERRUPT EXIT
MOV (SP)+,R5 ;POP UNWANTED LINK
DECB DXCNTX ;ALLOW RELEASE OF CUBSY
JSR R5,$WAKE ;TELL DX11 PROCESS TO DO IT ALL
JMP DXIXIT
;
; HERE ON SELECTIVE RESET - ASSUME HARDWARE HAS SET CUBSY (IT HAS NOT!)
DXIF12: MOV #XDHIO,R1
BIT #SELRST,R3 ;TEST FOR SEL RST
BEQ DXIHIE ;IF NOT MUST BE HIO
BIS #CUBSY,@#DXCS ;TRY TO FORCE CUBSY AS NOT DONE BY HARDW
DXISEX: BITB #XXRSTF,XXSTAT(R4)
BNE DXISY3 ;IGNORE IF ALREADY BEING RESET
MOV #XDRST2,R1
BITB #XXCMDF,XXSTAT(R4)
BNE 1$ ;B IF COMMAND ACTIVE
TSTB XXSTAT(R4)
BMI DXISY2;TO DO RST2 FOR FULLY READY DEV WITH NO ACTIVE CMD
1$: TST -(R1) ;SWITCH TO RST1 ROUTINE
BISB #XXRSTF!XXABOR,XXSTAT(R4);MARK ABORTING BECAUSE OF RESET
INCB DXCNTX;INTERLOCK AWAITING 'ENDING STATUS'
CLR DXCBSY
DXIHIE: BITB #XXNSTA,XXSTAT(R4);HIO ONLY RELEVANT DURING CMD PROCESSI
BEQ DXISY3;IGNORE IF PRESENTING STATUS OR NO CMD OUT
DXISE1:;CHDEND JOINS
BISB #XXABOR,XXSTAT(R4);MARK ABORTING
DXISY2: ADD XJUMP(R4),R1
MOV (R1),PC ;ENTER ACTION ROUTINE -RET TO TT SCAN OR SELRST
;
.PAGE
.SBTTL DX11 INTERRUPT ROUTINE - CODE FOR DRIVING OFFLINE DEVICES
;
;SENSE ISSUED FOR OFFLINE DEVICE R0/2
DXISPS:CMPB #SENSE,-1(R2) ;CHECK IF IN FACT SENSE
BNE DXER70 ;ERROR AS NOT SENSE
MOV #DXBAS1,R4 ;ADDRESS OFFLINE SENSE BASE
JSR R5,DXISC0 ;REMOVE NEW DEVICE FROM INITIALISING CHAIN IF
XXSNQ3,XXSCN3 ;NECESARY SHIFTING DOWN R0
TSTB XXSCNT ;LENGTH OF SENSE CHAIN IS 0
BEQ 2$ ;B IF CHAIN EMPTY
ASL R0 ;2(DEV ADDR)
CLR R1
BISB XDADDR(R4),R1 ;HEAD ITEM
ADD R1,R1
MOVB DXSPWT+DXSPWD(R1),DXSPWT+DXSPWD(R0) ;ADD TO CHAIN
ASR R0
TSTB XXSTAT(R4) ;IF OLD DEVICE DISPLAYING INIT STATUS
BPL 3$ ;DISPACE IT
MOVB R0,DXSPWT+DXSPWD(R1);ELSE QUEUE BEHIND IT
BR 1$
3$: MOVB XXSNQ3,DXSPWT+DXSPWD(R1);MOVE INTO INITIALISING CHAI
CLR DXBAST(R1) ;NO LONGER PSEUDO-OPEN
ASR R1
MOVB R1,XXSNQ3
INCB XXSNQ3
BIC #XXSTAF,XDFLAG(R4);CANCEL STATUS REQUEST
DECB XXSCNT ;ADJUST MAIN CHAIN COUNT
2$: JSR R5,DXISP2 ;FIRE UP SENSE DATA FOR NEW DEVICE
1$: INCB XXSCNT ;INCREMENT CHAIN LENGTH
DXISY3:RTS R5
DXER70:TRAP 7
;
;DISCONNECT DEVICE FROM OFFLINE BASE AND LOOK FOR WORK
;CALLED WHEN OFFLINE BASE REMOVED FROM DX WORK CHAIN
DXSB2:
CLR R1
BISB XDADDR(R4),R1 ;ADDRESS OF DEVICE JUST FINISHED
ADD R1,R1 ;2(DEV ADDR)
CLR DXBAST(R1) ;NO LONGER PSEUDO-OPEN
CLR R0
BISB DXSPWT+DXSPWD(R1),R0;NEXT DEVICE
DECB XXSCNT ;DEC USE COUNT
BEQ DXSB22 ;B IF ALL DONE
DXISP2:
MOVB R0,XDADDR(R4) ;SET SPECIAL BASE FOR THIS DEVICE
MOVB #SENSE,XXCMD(R4)
ADD R0,R0 ;2(DEV ADDR)
JSR R5,DXSBU1 ;PARTIAL BASE SETUP
.BYTE CE!DE,XXRDY!XXRDYF!XXCMDF ;STATUS FLAGS
JMP DXSENS
;START STATUS PRESENTATION FROM 2NDRY CHAIN - OFFLINE SENSE DEV BEEN HIO
DXSB22:
TSTB XXSCNS
BEQ DXSB25 ;B IF NONE TO DO
JSR R5,DXSBUP ;MOVE FIRST ITEM TO (EMPTY) FIRST QUEUE
XXSNQ2,XXSCNS
.BYTE CE!DE,XXRDY!XXRDYF!XXCMDF
BR DXSTP2
;
; ARE ANY STATUS PRESENTATIONS ON INITIALISING STATUS QUEUE
DXSB25:
TSTB XXSCN3
BEQ DXRTS1 ;B IF QUEUE EMPTY
JSR R5,DXSBUP ;MOVE TOP ITEM TO (EMPTY) FIRST QUEUE
XXSNQ3,XXSCN3
.BYTE CE!DE!UE,XXRDYF ;STATUS FLAGS
BR DXSTP2
;SUBROUTINE TO TAKE FIRST ITEM OFF 2ND OR 3RD QUEUES AND PUT ON 1ST Q
DXSBUP:
CLR R0
BISB @(R5),R0 ;GET DEVICE ADDRESS OF QUEUE
MOVB R0,XDADDR(R4) ;PUT ON FIRST QUEUE
ASL R0
MOVB DXSPWT+DXSPWD(R0),@(R5)+;MOVE UP QUEUE
INCB XXSCNT ;COUNT UP ITEM ON FIRST QUEUE
DECB @(R5)+ ;COUNT DOWN ITEMS ON OTHER QUEUE
DXSBU1: MOVB (R5)+,XSTATUS(R4);SET REQUIRED STATUS
MOVB (R5)+,XXSTAT(R4);AND DEVICE STATE
MOVB #INTREQ,XSENSE(R4);AND STANDARD SENSE DATA
MOV R4,DXBAST(R0) ;PSEUDO OPEN
DXRTS1: RTS R5
;
;ACTION SUBROUTINE JUMP TABLE FOR OFFLINE DEVICES
DXSNSJ: DXER70 ;COMMAND ENTRY MUST BE ERROR
DXRTS1,DXRTS1,DXRTS1 ;ERR ,CHD, HIO
DXRTS1,DXRTS1,DXSNS1 ;RST1, RST2, CAN'T HAPPEN DATA = SENSE
;
;SUBROUTINE CALLED BY DISPOSAL OF NORMAL SENSE DATA AFTER TRANSFER
DXSNS1:
MOV XJCOPY(R4),XJUMP(R4) ;RESET NORMAL JUMP TABLE
CLR XSENSE(R4) ;CLEAR SENSE BYTE(S)
CLR XSENSE+2(R4)
; FALL THROUGH TO STANDARD STATUS PRESENTATION
;
; STATUS PRESENTATION
; R4=DEVICE BASE
; USES R0,R1
;
DXSTPR: BITB #XXCMDF,XXSTAT(R4) ;ARE WE PROCESSING COMMAND
BEQ DXER37 ;ERROR IF NOT IN COMMAND
;
; IF DEVICE END NOT SET IN STATUS THEN DXSTPR WILL BE CALLED AGAIN
;
; CMPB #CE,XSTATUS(R4) ;LOOK FOR CHANNEL END
; BEQ DXSTP1 ;B IF MORE TO COME
;
DECB XCOUNT(R4) ;SHOULD SET TO -1
DXSTP1:
BICB #XXNSTA,XXSTAT(R4) ;MARK STATUS PRESENTATION
DXSTP2: MOV R4,R1
ADD #XDFLAG,R1
BISB #XXSTAF,(R1)
DXTR01: MOV @#PSW,-(SP)
MOVB #340,@#PSW ;SPL 7
TSTB (R1) ;TEST IF QUEUED
BPL DXTR00 ;JUMP IF BASE NEEDS QUEUEING (***FOR NOW
DXTR02: MOV (SP)+,@#PSW
DXSTP4: RTS R5
;
DXER37: TRAP 7
;
DXSTP3: BITB #XXRSTF,XXSTAT(R4)
BEQ DXTR00 ;QUEUE IT UNLESS RESETING
; PROCESS 'ENDING STATUS' AFTER A RESET
STPRST: BIT #DXTO+NPRTO,@#DXES ;TRAP TOO SLOW RESPONSE
BEQ 1$
TRAP 7
1$: MOVB #XXRDY!XXRDYF,XXSTAT(R4);TIDY UP FLAGS
CLRB XXCMD(R4) ;CLEAR OUT CURRENT COMMAND
BIC #XXSTAF,XDFLAG(R4);CANCEL STATUS REQUEST
MOV XJUMP(R4),R0
JSR R5,@XDRST2(R0) ;CALL RST2 SUBROUTINE TO MARK END OF RST
DECB DXCNTX ;COUNT DOWN DEVICES DOING RST PROCESSING
BNE DXSTP4 ;B IF NOT ALL FINISHED
DXRSR:
MOV #$DX11I,@#DXI ;RESET STANDARD IR (IN CASE OF SYS RST)
MOV #CUBSY,DXCBSY ;ALLOW CUBSY TO BE RESET ON IR EXIT
BIC #CUBSY,@#DXCS ;ACTUALLY RESET CUBSY UNLESS IR PENDING
MOV #DXCHN2,R1
MOV #DXQ1,R0
JMP $RECHN ;RECHAIN WORK HELD ON TO MAIN CHAIN
;
;
; INITIATE DATA TRANSFER
;
;
DXSENS: MOV R4,R1 ;SPECIAL ENTRY FOR SENSE
ADD #XSENSE,R1
MOV XNSNS(R4),R0 ;PICK UP NUMBER OF SENSE BYTES
NEG R0 ;NEGATED COUNT REQUIRED
DXTRAN: BITB #XXCMDF,XXSTAT(R4)
BEQ DXER37 ;ERROR IF NOT COMMAND
ADD #XDLEN,R4 ;POINT TO DATA LENGTH
MOV R0,(R4)+ ;SET DATA LENGTH
BPL DXTR03 ;COUNT EXHAUSTED
MOV R1,(R4)+ ;SET DATA ADDRESS
.IFDF MMU
; ASH #-12.,R1
; BIC #-16-1,R1 ;FIND PAGE NUMBER * 2
; MOV KISAR0(R1),XXAR-XDFLAG(R4) ;SET ADDRESS REGISTER
.ENDC
MOV @#PSW,-(SP)
MOVB #340,@#PSW ;SPL 7 - SET INTERLOCK
BIT #XXDATF+XXSTAF,(R4) ;CHECK NO OUTSTANDING ACTIVITY
BNE DXTER0
MOV R4,R1
SUB #XDFLAG,R4 ;*** RESTORE BASE POINTER
BITB #XXABOR,XXSTAT(R4) ;RETURN IF NO MORE DATA WANTED
BNE TRAN04
BISB #XXDATF,(R1) ;SET DATA TRANSFER REQUEST
BMI DXTR02 ;EXIT IF BASE ALREAY QUEUED
DXTR00:
BIS #XXCHNF,(R1)+;MARK CHAINED
MOV (SP)+,@#PSW
MOV #DXQ1,R0
JMP $SEND ;CHAIN REQUEST AND WAKE PROCESS
DXTR03: BNE 13$ ;ERROR IF POSITIVE COUNT
SUB #XDDATA,R4 ;****
BR TRAN01 ;RETURN REQUEST IF ZERO COUNT
13$: TRAP 7 ;INVALID LENGTH ( >0 )
DXTER0: TRAP 7 ;SENDING DATA WHEN ACTIVE
;
;REPORT TERMINATION OF DATA TRANSFER
;
TRAN04: MOV (SP)+,@#PSW
TRANOK: MOV XDDATA(R4),R1 ;GET RESIDUAL ADDRESS AND LENGTH
MOV XDLEN(R4),R0
BIC #XXDATF,XDFLAG(R4) ;CANCEL DATA TRANSFER REQUEST
TRAN01: MOV #XDTRAN,-(SP)
ADD XJUMP(R4),(SP)
MOV @(SP)+,PC ;CALL USER SUBROUTINE - THEN RETURN
;
;
; OPEN A DEVICE
; CALL AS SUBROUTINE ON DEVICE BASE
; XDADDR MUST HAVE BEEN SET (R5)+ IS NEW SPW
; N.B. NOT INTERLOCKED - MAY ONLY BE CALLED WHILE DISABLED DURING
; SYSTEM INITIALISATION
;
DXOPEN:
CLR R0
BISB XDADDR(R4),R0 ;DEVICE ADDRESS
ADD R0,R0
CLRB XSTATUS(R4) ;INITIALISE STATUS
JSR PC,DXNIT2 ;INITIALISE MOST FIELDS
CLR XDFLAG(R4) ;NO DEVICE REQUESTS
MOV R4,DXBAST(R0) ;SET BASE TABLE
MOV (R5)+,DXSPWT(R0);AND SPW
MOV (R5)+,XJUMP(R4) ;SET ACTION SUBROUTINE TABLE
JMP DXSTP2
;
DXNIT2:
MOVB #XXRDYF,XXSTAT(R4)
MOVB #CHEND!DEVEND!UXCEP,XSTATUS(R4) ;SET INTIALISING STATUS
CLR XSENSE(R4) ;CLEAR SENSE BYTE(S)
CLR XSENSE+2(R4)
CLRB XXUFLAG(R4) ;CLEAR USERS FLAGS
MOVB #-1,XCOUNT(R4) ;INIT COUNT OF ACTIVE BUFFERS
CLR XSEM(R4) ;INITIALISE SEMAPHORE
CLR XSEM+2(R4)
RTS PC
;
.PAGE
.SBTTL INITIALISE DX11
;
DXINIT:
MOV #CUBSY!GO,@#DXCS;CLEAR DONE,SET CUBSY ,RESET DX1
MOV #-1,@#DXBC ;FORCE QUICK TERMINATION OF ANY TRANSFER
BIT #ONLINB,@#DXCB
BNE DXINIT ;LOOP TILL OFFLINE
MOV #CUBSY!GO,@#DXCS;ENSURE RESET
MOV #DXSPWT,@#DXOS ;SET SPW/DST POINTER
; ZERO TT,BASE TABLE, SET SPW'S
MOV #DXTT+DXTTL,R0
DXNITL: CLR -(R0)
MOV #UC,-DXSPWL(R0) ;AND SET UC AND DST PTR=0 IN SPW TABLE
CMP R0,#DXTT
BHI DXNITL ;LOOP FOR ALL DEVICES
MOV #DXBSTA,R0
DXNITB:
CLR (R0)+ ;CLEAR BASE TABLE
CMP R0,#DXBSTB
BLO DXNITB
;
MOV #DXTT,DXTTP ;RESET SOFTWARE TT POINTER
CLR DXCNTX ;CLEAR CHAINING MARKER AND CNT OF DEV
;NOT YET FINISHED RESETING
CLR DXCHN2 ;CLEAR SUBSIDARY CHAIN
MOV #CUBSY,DXCBSY ;SET FOR CLEARING CUBSY
MOV #SWNORM,DXIRSW ;SET STANDARD INTERRUPT STATE
;SET UP DUMMY BASE FOR OFFLINE SENSES
MOV #DXBAS1,R4
JSR PC,DXNIT2 ;PERFORM MOST OPEN OPERATIONS
MOV #XXOFFF,XDFLAG(R4);REQUEST SPECIAL TUDYUP OPERATION
CLR XXSCNT ;CLR CNT OF DEV ON OFFLINE SENSE CHAINS
MOV #DXSNSJ,XJUMP(R4);SET ACTION S/R JUMP TABLE ADDRESS
CLRB XXSCN3 ;CLEAR Q3
MOV #240,@#DXI+2 ;IR AT PRIORITY 5
MOV #$DX11I,@#DXI ;IR ENTRY POINT
5$:
BIS #ONLINA!ENDEN!CUBSY,@#DXCS;PUT ONLINE BUT NO INTERRUPTS
BIT #ONLINB,@#DXCB ;LOOP UNTIL ONLINE
BEQ 5$
RTS R5 ;NO OFFLINE DEVICE INTIALISATION PRO TEM
;
;QUEUE OFFLINE DEVICE INTIALISING STATUSES
;
DXNITT:
MOV #DXBAS1,R4
MOV #DXDEV1,R0 ;LOWEST DEVICE SUPPORTED
DXNITP: MOV R0,R1
ASL R1
TST DXBAST(R1)
BNE 1$ ;B IF DEVICE ONLINE
MOVB XXSNQ3,DXSPWT+DXSPWD(R1);)ADD TO QUEUE
MOVB R0,XXSNQ3 ;)
INCB XXSCN3 ;COUNT UP NUMBER TO DO
1$:
INC R0
CMP R0,#DXDEV2 ;CHECK FOR HIGHEST ADDRESS SUPPORTED
BLT DXNITP ;LOOP FOR ALL DEVICES
JMP DXSB25
.PAGE
.SBTTL CAMBRIDGE SYSTEM ROUTINE SIMULATION
;UNCHAIN FROM QUEUE
;R0 IS ADDRESS OF QUEUE POINTER
;R1 IS ADDRESS OF XCHAIN FIELD OF BASE ON RETURN
$UCHAIN:MOV @#PSW,-(SP)
MOVB #340,@#PSW
MOV (R0),R1
BNE UCHN1
TRAP 7 ;EMPTY QUEUE
UCHN1: MOV (R1),(R0) ;DEQUEUE
MOV (SP)+,@#PSW
RTS R5
;
;CHAIN BASE WHOSE XCHAIN FIELD ADDRESS IS IN R1
;R0 IS ADDRESS OF QUEUE POINTER
$CHAIN: MOV @#PSW,-(SP)
MOVB #340,@#PSW
1$: TST (R0)
BEQ TCHN ;FOUND TAIL OF QUEUE
MOV (R0),R0 ;FIND NEXT BASE ON QUEUE
BR 1$
TCHN: MOV R1,(R0) ;ADD TO TAIL OF QUEUE
CLR (R1) ;CLEAR LINK(XCHAIN)
MOV (SP)+,@#PSW
RTS R5
;WAKE DX11 PROCESS
$WAKE: MOV SP,R0
SUB #12,SP ;SET NEW STACK BASE
MOV #DXSEM,-(R0)
JSR PC,$V
ADD #12,SP ;RESET STACK
RTS R5
;
;
$RECHN: MOV @#PSW,-(SP)
MOVB #340,@#PSW
1$: TST (R0) ;CHECK FOR TAIL OF QUEUE
BEQ RCHN2
MOV (R0),R0 ;CHAIN DOWN QUEUE
BR 1$
RCHN2: MOV (R1),(R0) ;JOIN QUEUES
CLR (R1)
JSR R5,$WAKE
MOV (SP)+,@#PSW
RTS R5
;
$SEND: MOV @#PSW,-(SP)
MOVB #340,@#PSW
JSR R5,$CHAIN
JSR R5,$WAKE ;WAKE DX11 PROCESS
MOV (SP)+,@#PSW
RTS R5
.END