Skip to content

SINTRAN III Output-Spooling Internals - Carved (byte-verified) Findings

Version under analysis: L-VSX-500 (L07). K-VSX-500 / M-VSX-500 used for segment-presence comparison. Carve tree: ../../tools/sintran-segment-carver/versions/L-VSX-500/segments/ Symbols: ../NPL-SOURCE/SYMBOLS/L07/ (SYMBOL-1-LIST, SYMBOL-2-LIST, l07-kallsyms.txt) Method: static RE per the sintran-carving skill. Carved big-endian bytes = ground truth; nd100-dis after byte-swap. Every address below reproduced from bytes with dd/python before publishing.

Conventions in this document: octal for all SINTRAN addresses; hex for any Ghidra base; memory in words (bytes in parens); ASCII only. "VERIFIED" = read from carved bytes myself. "DOCUMENTED" = from an official manual, not (yet) proven in these bytes. Anything not established is marked NOT RESOLVED.

0. Summary table (what each piece is)

Piece Segment (load base) Role Status
Queue manager (add/dequeue file, page-pool wait/wake) 006-S3FS (base 26000B) MON-call workers APSPF/SPCLO/RSPQE + the queue list handlers + the page-pool reserve/release VERIFIED (MCTAB slots, entry disassembly, wait/wake sequence)
Spooler control-block table SPTAB=122562B .. ENDSP=123034B, stride SPLEN=12B (10 words), ~17 slots one control block per spooler (per device): SPROG=+1, SPERI=+2 peripheral LDN, SPINX=+10B spool index VERIFIED (symbols + NPL stride)
Per-file spooling queue dedicated queue segment, VA 150000B-177777B; list head LSPOQ=162122B linked records keyed by file/job/user, carry page count SPAGE=+31B VERIFIED (offsets + RSPQE walk)
Spooling datafield SAVE area 031-S3SSPD (base 164000B; K/L/M) saved copy of each SPPRx (SPRTx) spooling-program datafield VERIFIED (QSEMAPHORE/QIOSEMAPHORE anchor)
Physical line-printer driver per-device IOX cells in 044-S3IDPIT / 053-S3SDPIT (base 4000B) + device-dependent HEAPR/TRAPR/SPRIN executes IOX 430B..433B against the printer VERIFIED (IOX cells)
Remote (COSMOS) spooling 137-COSPOOL (L only) holds COSPO RT program network/remote printing via XMSG; NOT local output spooling role DOCUMENTED, byte-consistent
Background spooling program body (the SPOOL routine SPRTx runs) NOT located in bytes 120-S3SPRMA is an L/M spooling segment but its content is not overlay-proven NOT RESOLVED

Key correction to the framing of the request: the spooling QUEUE MANAGER is not in 031-S3SSPD nor 137-COSPOOL - it is in the file-system segment 006-S3FS (the MON-call workers + queue handlers + page-pool semaphore). 031-S3SSPD is a datafield save area (data, not code). 137-COSPOOL is COSMOS remote spooling, a separate subsystem.

POISONED PRIOR corrected in this document (see section 1.2): SPOOL=147510B is the buffer/page pool gate, NOT the spooling program body. An earlier draft here decoded 147510B as code in the 120-S3SPRMA overlay and called it the program - that was the overlay trap (symbol in a resident data region). The spooling-program body location is now marked NOT RESOLVED.

1. Segment roles: 031-S3SSPD, 137-COSPOOL, 120-S3SPRMA

1.1 031-S3SSPD - "Save of spooling data fields" (K/L/M) - VERIFIED as DATA

  • Meta: 031-S3SSPD.meta.json says "Save of spooling data fields", 1 page = 1024 words (2KB), load base 164000B (0xE800).
  • Present in K, L and M (verified by directory listing).
  • Content is data, not code: word[0]=164000B (self/load-address marker), word[1]=177777B, word[2]=165123B, then a long run of zeros, then a small pointer/value table from 164047B on.
  • It holds saved SPPRx spooling-program datafields. Byte-anchored against the documented SPPRx layout (ND-60.112.01 Data Fields, Data Field Layout "SLPx / SPPRx"):
    • 164047B = 1136B = QSEMAPHORE (SPPRx rel +4) -- VERIFIED
    • 164050B = 1137B = QIOSEMAPHORE (SPPRx rel +5) -- VERIFIED
    • 164054B/164055B/164056B = 172330B / 172646B / 171675B = saved device-dependent routine addresses (TRAILER/PRINTBUFFER/FILENUMBER region). This two-value semaphore anchor (1136B,1137B adjacent) matches the manual's rel+4/rel+5 exactly, which is what pins 031-S3SSPD to the SPPRx datafield save.
  • This is the <save-area?> operand referenced by *SET-SPOOLING-DEVICE-NUMBER (see section 3).

1.2 SPOOL=147510B is the buffer/PAGE-POOL gate (VERIFIED) - not the program body

  • SPOOL=147510B, RPOOL=147511B, NPOOL=147512B, BPOOL=147715B are a group of adjacent buffer/page-pool cells (from SYMBOL-1-LIST / FILSYS-SYMBOLS). SPOOL is the free-buffer gate: NPL CC-P2-COMMON.NPL:431 reads IF SPOOL=0 THEN % NO BUFFERS FREE (verified in that source). They are grouped as pool cells in the 006-S3FS reference table at 114745B-114752B (BPOOL,NPOOL,-,BPOOL,SPOOL,RPOOL), and the DPIT relocation table places {RPOOL,SPOOL} directly beside the wait/reserve/release primitives {WAITF,RESRV,RELES} (section 4.3). Resident pointer SSPOO=004274B holds 147510B = a pointer to the SPOOL pool cell (VERIFIED), i.e. it points at the pool head, not at a program.
  • Correction / poisoned prior: an earlier draft of this file read 147510B as executable code in the 120-S3SPRMA overlay and called it "the spooling program body". That was the classic overlay trap (skill traps 4 and 8): a symbol that names a resident data cell also decodes as unrelated code in a segment that happens to span the same virtual address. SPOOL=147510B is the pool gate.
  • 120-S3SPRMA is present in L and M and absent in K (verified by listing) - so it is a spooling segment introduced at the L/M generation - but its exact contents are not byte-proven here, and the manual's SPPRx rel-0 label "SPOLPROGRAM = SPOOL" is a datafield-layout label, not proof that L07 symbol SPOOL is the program entry.
  • NOT RESOLVED: the byte location of the common spooling-program routine that the SPRTx RT programs execute.

1.3 137-COSPOOL - COSMOS REMOTE spooling (L only) - role DOCUMENTED, byte-consistent

  • Present in L only (verified). Meta has no load address and no description; 18 pages (18432 words); flag 000100B.
  • Contains no local device I/O: scanning all 18432 words found zero IOX (164xxx) and zero MON (1534xx) instruction words - VERIFIED. So it is neither the physical printer driver nor a MON-issuing background program in the local sense.
  • Disassembled (base 0) it is real code that manipulates the paging control register (TRR PCR, IOF/ION, BSET ... SSPTM) - i.e. it installs/uses its own page table.
  • Role (DOCUMENTED): segment COSPOOL holds COSPO, the COSMOS SPOOLING RT program = remote spooling (printing to printers on other systems over XMSG). Sources: ../../Installation/Communication/COSMOS Basic/COSMOS-Basic-Install-Guide.md lines 197-198 ("chain COS-COSP-VSX-E02:MODE (loads COSPO into segment COSPOOL, SET-PAGE-TABLE 1)") and 215 ("RTON COSPO; START-SPOOLING COSMOS-SPOOLING"). The SET-PAGE-TABLE 1 step matches the byte-observed paging-register code above.
  • This is a separate subsystem from local output spooling and does not implement the local print-queue manager, the local printer driver, or the SPRTx local scheduler.

2. MON calls APSPF (240B) and SPCLO (40B) - dispatch + workers + register conventions

2.1 Dispatch (via the MCTAB model) - VERIFIED

Per the byte-verified MON dispatch model (MON N -> ENT14 -> GOTAB[N]=MFELL -> CALLP -> MCTAB[N]), the worker address is MCTAB[N], MCTAB=9MCTA=005620B in segment 044-S3IDPIT (base 4000B). MCTAB validated against known slots before use (skill trap 2): MCTAB[5B]=102021B (RDISK), MCTAB[144B]=026354B (MAGTP) - both correct.

MON Name MCTAB slot (addr) Worker Worker seg Status
240B AppendSpooling APSPF MCTAB[240B] @ 006060B = 106307B APSPF=106307B 006-S3FS VERIFIED
40B CloseSpoolingFile SPCLO MCTAB[40B] @ 005660B = 067572B SPCLO=067572B 006-S3FS VERIFIED
55B GetSpoolingEntry (RSPQE) MCTAB[55B] @ 005675B = 106212B (no L07 symbol) 006-S3FS VERIFIED (worker word)

APSPF=106307B and SPCLO=067572B also match the symbol tables (l07-kallsyms: APSPF=0x8CC7=106307B, SPCLO=0x6F7A=067572B). All three workers sit in the file-system segment 006-S3FS (base 26000B, which spans 26000B..177777B); GetSpoolingEntry's worker (106212B) is right below APSPF (106307B) - one clustered spooling-queue-manager region.

2.2 Worker entry points - VERIFIED from bytes

  • SPCLO @ 067572B begins 021131 STD I 131 (save link), then (067577B..067617B) sets a print/condition flag in ,B 42, then at 067620B..067630B does SAA -1 / SKP IF DT UEQ SA and SAA -2 / SKP IF DT UEQ SA and SKP IF DT UEQ 0 - i.e. it tests the T register (DT) against -1/-2/0. This byte-confirms T = file number (the SPCLO "File Number" parameter). VERIFIED.
  • APSPF @ 106307B begins 021046 STD I 46 (save the incoming D register = the UserText pointer), then calls helper routines (JPL I 43 -> 106356, JPL I 40 -> 106360, ...), and at 106363B issues IOT 3233. Entry + D-save VERIFIED.

2.3 Register / parameter conventions - cross-checked vs the Monitor Calls manual

Source: ../../Reference-Manuals/ND-860228-2-EN SINTRAN III Monitor Calls.md.

AppendSpooling (MON 240B), MAC calling sequence (manual p.79, lines 3196-3213): - X = address of file name (to be printed; name may be abbreviated) - T = number of copies in bits 0:14; bit 15 = 1 means "also print the UserText message" - A = address of UserText message, then COPY SA DO so D = message address - A = address of the spooling-device (printer) peripheral-file name (loaded last, live at MON) - Return: A = standard error code (0 = OK). - Byte cross-check: worker saves D first (STD I 46) = the message pointer per the convention.

CloseSpoolingFile (MON 40B), MAC calling sequence (manual p.118-119, lines 5013-5026): - T = file number (from the earlier open) - A = number of copies, then COPY SA D0 so D = number of copies - A = condition/print flag (0 = only print text if @DEFINE-SPOOLING-CONDITIONS requires it; non-zero = print unconditionally) - X = address of the error-device text - Return: A = standard error code. - Semantics: if the file is not a spooling file, a normal close is performed (manual line 4921). - Byte cross-check: worker tests T (DT) = the file-number parameter. VERIFIED.

3. The *SET-SPOOLING-DEVICE-NUMBER "spooling index" and the peripheral-file "versions" mechanism

These are two different structures that meet at a device number.

3.1 The spooling index -> the spooling-programs table (DOCUMENTED)

  • *SET-SPOOLING-DEVICE-NUMBER <spooling index> <logical device number> (<memory?>) (<image?>) (<save-area?>) is a SINTRAN Service command, not a monitor call (so it is absent from the Monitor Calls manual). Source: ../../Operations/SINTRAN/ND-30.003.007 EN SINTRAN III System Supervisor.md lines 9926-9962, 9984.
  • The spooling index is the identity of a spooling PROGRAM. SINTRAN is generated with N system-included RT-programs called SPRTx, where x = the spooling index. SPRT1 = index 1, SPRT2 = index 2, ... indices run from 1 upward. Source: ../../Reference-Manuals/ND-60.128.5 EN SINTRAN III Reference Manual.md line 10837.
  • So the index indexes into the parallel spooling tables: the "spooling device numbers" table (index -> the printer's logical device number that this SPRTx serves) and the "define printer type" table (same index -> printer-type). The command writes the LDN (and the three segment numbers <memory?> = the in-memory datafield, <image?> = the datafield image on the segment file, <save-area?> = the save-area segment = 031-S3SSPD) into entry [spooling index]. Source lines 9956 ("The index in this table now corresponds to the spooling index") and 9941.
  • The SPRTx runtime datafield (SPPRx, see section 1.1 / 4) carries the effective binding: rel +2 DEVNO = peripheral logical device number, rel +3 QSEGMENTS = the queue segment number, rel +4/+5 = the queue / queue-I/O semaphores.

Byte status of the "spooling device numbers" table itself: NOT RESOLVED. I did not byte-locate the resident table that *SET-SPOOLING-DEVICE-NUMBER writes. Candidate resident data cells exist (SPQSS=005117B, PAGPN=005223B, SSPOO=004274B) but the table's own address/stride is not proven here. (The byte-verified spooler tables that DO exist are SPTAB=122562B with SPINX=+10B, and the per-file queue off LSPOQ=162122B - see section 4.1.) What is verified: SSPOO=004274B = 147510B (= SPOOL, the buffer-pool gate, section 1.2), and the save-area segment is 031-S3SSPD.

3.2 The peripheral-file "versions" mechanism (DOCUMENTED)

Source: ../../Reference-Manuals/ND-60.050.06 SINTRAN III Users Guide.md lines 3822-3844.

  • "A peripheral file may be created in more versions than the existing number of corresponding peripherals. All versions of the file not connected to a device number will be treated as spooling files."
  • Worked example (manual):
    • @CREATE-FILE LINE-PRINTER;10,0 -> ten versions of file LINE-PRINTER.
    • @SET-PERIPHERAL-FILE LINE-PRINTER, 5 -> version 1 is bound to device number 5 (the real printer). Versions 2..10 have no device number -> they are spooling files.
    • @START-SPOOLING LINE-PRINTER starts output spooling if a spooling program was generated for device 5.
  • The connection between the two structures: the peripheral file's device number (5 in the example) is the same LDN that a SPRTx/spooling-index entry serves (its DEVNO). When a user opens the peripheral-file name, an unbound (device-less) version is used as the spooling file; on close/append (APSPF/SPCLO) it is queued to the spooling program serving that device.
  • The device number lives in the file-system object entry: LDN in bits 0-11, unit number in bits 12-15 (Monitor Calls manual line 17962). A version with no device number = spooling file.

4. The spooling QUEUE data structure + "currently printing not in queue" + page-pool wait/wake

4.1 Two distinct records - VERIFIED (symbols + NPL stride + disassembly)

There are two structures, not one:

(a) Per-spooler control block - array SPTAB=122562B .. ENDSP=123034B, stride SPLEN=12B (10 words). (ENDSP-SPTAB)/SPLEN = 252B / 12B = ~17 spooler slots. One block per device (spooler), NOT per queued file. Field offsets (FILSYS-SYMBOLS, VERIFIED): SPROG=+1 (the spooler RT-program ref), SPERI=+2 (peripheral logical device number; set to -1 to disable a spooler), SPMOD=+30B, SPAGE=+31B, SPFNA=+35B, SPINX=+10B (spool index). The stride and iteration X := X + SPLEN are corroborated in NPL (PH-P2-OPPSTART.NPL, RP-P2-CONFG.NPL; logic only).

(b) Per-file spooling-queue ENTRY - a linked record in a dedicated spooling-queue segment whose VA window is 150000B-177777B (PH-P2-OPPSTART.NPL:1374 "ADDR 150000-177777 IS AVAILABLE FOR SPOOL.QUEUE"; size = config param SPQSSIZE). List head / anchor LSPOQ=162122B (referenced by pointer from 003-S3CP and the user segments 110/111/112/113). Field offsets in the entry (VERIFIED symbols): SPMOD=+30B mode/flags, SPAGE=+31B page count of the queued file, SPFNA=+35B file name, SPUME=+71B user, 3-word job name SPJN1/2/3=+151B/152B/153B, SPMES=+161B message text. The record is >= 114B words - far larger than an SPTAB element, confirming these are different tables. RSPQE (release spool-queue entry, worker of MON 55B GetSpoolingEntry) at 006-S3FS 106212B walks the chain via LDA ,X 17 / LDX ,X 31 (offset 31B = SPAGE). Other resident queue handlers: GSPQB=034267B/RSPQB=034305B (get/return queue block), MSPQE=165567B. So a queue entry is a dedicated linked record in a separate spool-queue segment, keyed by file/job/user and carrying its page count - it is NOT stored in the normal open-file object tables.

API view of the same entry: at the MON boundary GetSpoolingEntry (MON 55B) presents a 272-byte record (Monitor Calls manual lines 12278-12291): bytes 0:1 copies, 2:3 apostrophe flag, 4:97 spooling-file name, 98:255 error-device message. This is the caller-facing projection of the in-segment entry above.

4.2 "The file currently printing is NOT in the queue"

  • API/DOCUMENTED: GetSpoolingEntry (MON 55B) "gets the next spooling queue entry ... The entry is removed from the spooling queue" (manual line 12280). The spooler pulls the head into its private SPTAB control block and prints from there, so it is no longer on the LSPOQ list.
  • Building blocks VERIFIED: the queue is a linked list off LSPOQ=162122B; the resident has generic list insert/remove primitives (XINSP/XREMP/YINSP/YREMP, 006-S3FS ~034410B-034451B) and the release worker RSPQE=106212B.
  • NOT RESOLVED (byte level): the exact instruction sequence that unlinks the current entry from LSPOQ into the spooler's control block was not traced. The removal is manual-documented and structurally consistent, but not byte-proven here.

4.3 Page-pool wait/wake (default 500 pages) - VERIFIED

The wait/wake is a SINTRAN semaphore reserve/release, byte-verified in 006-S3FS at 171001B-171013B (all words re-read from bytes in this session):

171001  044011  LDA 11           ; A := word@171012 = SPSEM pointer
171002  153122  MON 122          ; 2RESR = RESERVE semaphore -> BLOCKS caller (page-pool WAIT)
171003  130002  JAP 2
171004  135007  JPL I 7   -> 171013   ; error path
171005  044005  LDA 5            ; A := SPSEM pointer
171006  153123  MON 123          ; 2RELE = RELEASE semaphore -> WAKES first waiter
171007  130002  JAP 2
171010  135003  JPL I 3   -> 171013
171011  153000  MON 0            ; LEAVE
171012  164607  <data>           ; = SPSEM pointer (164607B)
  • 2RESR=122B and 2RELE=123B are VERIFIED symbols (FILSYS-SYMBOLS / SYMBOL-1-LIST), and the words 153122B/153123B/153000B/164607B at 171002B/171006B/171011B/171012B were verified directly from the carved bytes. MON 122B reserving a held semaphore puts the caller in the semaphore's waiting queue; MON 123B (RELES) removes the first waiter and inserts it into the execution queue (semantics: ../OS/21-SEMAPHORES-EXPLAINED.md). That is exactly "writer blocks when the pool is empty / spooler wakes it when pages are freed".
  • The semaphore is the spool-semaphore cluster FSPSM=164601B, SPSEM=164607B, USPSM=164612B in the spool-queue segment.
  • Pool counter cells: SPOOL=147510B (free-buffer gate; NPL CC-P2-COMMON.NPL:431 IF SPOOL=0 THEN % NO BUFFERS FREE), RPOOL=147511B, NPOOL=147512B, BPOOL=147715B. Independent corroboration that the pool accounting sits next to the wait primitives: the 044-S3IDPIT / 053-S3SDPIT relocation table bundles RPOOL(147511B) / SPOOL(147510B) immediately beside WAITF=043717B / RESRV=037103B / RELES=037156B.
  • PAGPN=005223B reads 0 in the static 044-S3IDPIT image (VERIFIED) - consistent with the 500-page default being a generation/warm-start configuration value, not baked into the carve.
  • NOT RESOLVED (byte level): the precise SPOOL decrement-on-allocate -> fall-into-RESRV/block, and the spooler's increment -> RELES ordering was not traced end to end. The wait/wake primitive (171001B-171013B) and the pool cells are byte-verified; the exact decrement/increment sequence around them is inferred from the co-located pointer table + CC-P2-COMMON logic.

5. Line-printer physical driver - IOX sequence for device 430B (CDC 9380)

5.1 Manual register map (CDC 9380) - DOCUMENTED

Source: ../../Reference-Manuals/ND-06.016.01_NORD-100_Input_Output_System.md Appendix B (section B.3). Standard device numbers 0430B-0433B, interrupt level 10 (dec), ident 3.

IOX offset Dir Function
DEV+0 = IOX 430 Read Read Data Word (read back buffer; test mode)
DEV+1 = IOX 431 Write Write Data Word (character into buffer)
DEV+2 = IOX 432 Read Read Status Word
DEV+3 = IOX 433 Write Write Control Word

Write Control (+3) bits: b0 int-enable-on-ready, b1 int-enable-on-error, b2 activate (print buffered char), b3 test, b4 device+interface clear. Read Status (+2) bits: b3 ready-for-transfer, b4 error, b5 not-ready, b6 out-of-paper, etc. (Note: the task hint "data register = 1" matches DEV+1 = Write Data; but per the manual DEV+0 is Read Data and DEV+2 is Read Status, not "+0 = status".)

5.2 Carved driver IOX cells - VERIFIED

The device number 430B is baked into IOX-instruction cells inside the line-printer device datafield (DPIT), found identically in both DPIT copies (base 4000B): 044-S3IDPIT.bin ("Image of DPIT") and 053-S3SDPIT.bin ("Save of DPIT"). Raw big-endian words verified directly:

LP1 (device 430B):

VA (oct) Word (oct) Instruction Manual meaning
106770 164433 IOX 433 LP1 Write Control
106771 164432 IOX 432 LP1 Read Status
106772 164431 IOX 431 LP1 Write Data
107003 164430 IOX 430 LP1 Read Data

LP2 (device 434B), parallel block +346B words later:

VA (oct) Word (oct) Instruction Manual meaning
107336 164437 IOX 437 LP2 Write Control
107337 164436 IOX 436 LP2 Read Status
107340 164435 IOX 435 LP2 Write Data
107351 164434 IOX 434 LP2 Read Data

Structural coherence: LP2 is an exact copy of the LP1 template shifted +346B words; both have a contiguous Control/Status/WriteData triple then a Read-Data cell +13B words later (107003-106770 = 107351-107336 = 13B). This is the standard SINTRAN pattern: the common line-printer driver code executes these per-device IOX cells in place, so the device number lives in the datafield, not in shared code. (All eight words re-verified against raw bytes in this session.)

NOT RESOLVED: the generic (shared) line-printer driver code body that dispatches/executes these IOX cells was not located as a distinct L07 symbol (the DPIT cells are the byte-anchored artifact).

6. Resolved vs. open

Resolved (byte-verified): - MON 240B APSPF and MON 40B SPCLO dispatch via MCTAB (240B@006060B=106307B, 40B@005660B=067572B), plus MON 55B GetSpoolingEntry worker @005675B=106212B; all workers in 006-S3FS; entries disassembled; SPCLO T=file-number and APSPF D=message-ptr confirmed in code. - 031-S3SSPD = SPPRx spooling-datafield SAVE area (QSEMAPHORE=1136B/QIOSEMAPHORE=1137B anchor); present K/L/M. - 137-COSPOOL = no IOX / no MON, paging-register code = COSMOS remote-spooling COSPO (L only, documented + byte-consistent). - Queue data structures: per-spooler control block SPTAB=122562B..ENDSP=123034B stride SPLEN=12B (~17 slots, fields SPROG/SPERI/SPINX/SPAGE); per-file queue = linked records in the queue segment VA 150000B-177777B off head LSPOQ=162122B, fields SPMOD/SPAGE/SPFNA/SPUME/SPJNx/SPMES; walked by RSPQE=106212B. - Page-pool wait/wake = semaphore reserve/release at 006-S3FS 171001B-171013B (MON 122B 2RESR block / MON 123B 2RELE wake on SPSEM=164607B); pool gate SPOOL=147510B (=0 => no buffers free). - Line-printer IOX cells for device 430B (and 434B) in DPIT (044/053), mapped to the CDC 9380 manual register set.

Open / NOT RESOLVED: - The resident "spooling device numbers" table that *SET-SPOOLING-DEVICE-NUMBER writes (distinct from the byte-verified SPTAB; the command's exact target/stride is unconfirmed) - section 3.1. - The byte location of the common spooling-program routine (SPOOL label is the pool gate, NOT the program; 120-S3SPRMA content not overlay-proven) - sections 1.2, 0. - The exact SPOOL decrement->block (writer) and increment->wake (spooler) instruction ordering around the verified reserve/release primitive - section 4.3. - The byte-level unlink of the currently-printing entry from LSPOQ - section 4.2. - The generic line-printer driver code body that runs the DPIT IOX cells - section 5.2.

Cross-checked manuals: Monitor Calls (ND-860228-2), NORD-100 I/O System (ND-06.016.01) App B, System Supervisor (ND-30.003.007), Users Guide (ND-60.050.06), Reference Manual (ND-60.128.5), Data Fields (ND-60.112.01), COSMOS Basic install guide.