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MON 41B (octal) - ReadObjectEntry (ROBJE)

CORRECTED 2026-07-15 (byte-verified). The worker + dispatch described below are on the DEBUNKED model and are WRONG. Byte truth from the carved L07 image: MCTAB[41B] = 005661B = MROBJ=104035B in segment 006-S3FS, reached by the real dispatch MON 41B -> ENT14(072167B) -> GOTAB[41B]=MFELL(072114B) -> CALLP(032201B) -> MCTAB[41B]=MROBJ. Any "GOTAB from commoncode" / "uncarved CALLPROC bridge" / "F16xx stub" / old worker name below is an artefact of the wrong table. Verified: dd if=044-S3IDPIT.bin bs=1 skip=1890 count=2 -> 88 1d. Cross-ref ../317B-ExecuteCommand/README.md and SINTRAN/CARVING-HANDOFF.md sec 3a.

Gets information about an opened file. Each file has an object entry - a 64-byte record holding the file name, access rights, the dates last opened for read and write, the size, and the device/unit number where the mass-storage file resides. The caller passes the file number and the address of a 64-byte receive buffer.

Status: GOTAB dispatch head byte-proven (GOTAB[41B] = 121023B, the F1627 level-14 vector in 025-S3IRPIT); the ROBJE worker body is real SINTRAN L bytes and walks the object-entry structure via the file-system primitives (FOBJB, GDDRT, RINDX, RBLOC, RELBU); the exact MON 41 -> worker link crosses an uncarved kernel bridge (see Honest caveats). All addresses/values are octal.

Dispatch path

flowchart LR
    A["User program<br/>MON 41B"] --> B["ENT14 level-14<br/>T = MON number"]
    B --> C["GOTAB[41B] = 121023B<br/>(byte-proven)"]
    C --> D["F1627 entry vector<br/>025-S3IRPIT :121023B"]
    D -.uncarved CALLPROC.-> E["ROBJE read-object-entry worker<br/>006-S3FS :55566B"]
    E --> F["FOBJB / GDDRT / RINDX / RBLOC / RELBU<br/>file-system primitives"]
    class A blue
    class B,C,D teal
    class E,F green
    classDef blue fill:#E3F2FD,stroke:#0D47A1,color:#0D47A1
    classDef teal fill:#E0F7FA,stroke:#00838F,color:#00838F
    classDef green fill:#E8F5E9,stroke:#2E7D32,color:#2E7D32

The dashed hop (D -> E) is the resident CALLPROC/segment-switch - it is not present in any carved segment, so it is the one link that cannot be followed statically.

Code location (dispatch path)

Every row is a real region you can open. The byte offset is the authoritative decimal byte offset from the segment .hex (the 025-S3IRPIT carve has an unmapped hole before the vector, so its offset is not the plain (addr - loadbase) x 2).

Role Segment (full disasm) Addr range (octal) Byte offset Symbol Verdict
GOTAB[41] dispatch word commoncode.asm - .hex 071274B (1 word) 58744 GOTAB+41 = 121023B VERIFIED
F1627 entry vector 025-S3IRPIT.asm - .hex 121023B-121032B (8w) 56358 F1627 VERIFIED (vector/link-cell data)
resident CALLPROC bridge - (uncarved) - - CALLPROC UNVERIFIED
ROBJE worker body 006-S3FS.asm - .hex 55566B-55747B (code to 55725B) 24300 ROBJE real bytes; link MISATTRIBUTED

Verify by hand: grep '^55566 ' ../../segments-ref/006-S3FS/006-S3FS.hex -> byte offset 24300; then dd if=../../../segments/006-S3FS.bin bs=1 skip=24300 count=8 | od -An -tx1 -> 22 60 cc 65 cc 59 f0 08 (= octal 021140 146145 146131 170010 = STD I 140 / RADD CLD SL DA / RADD CLD SB DD / SAB 10, the ROBJE entry).

The GOTAB slot itself: dd if=../../../resident/SINTRAN-DATA_commoncode.bin bs=1 skip=58744 count=2 | od -An -tx1 -> a2 13 (big-endian word = 121023B).

The F1627 vector: grep '^121023 ' ../../segments-ref/025-S3IRPIT/025-S3IRPIT.hex -> byte offset 56358; then dd if=../../../segments/025-S3IRPIT.bin bs=1 skip=56358 count=2 | od -An -tx1 -> 62 70 (= 061160B, the first vector word).

Instruction walkthrough

Full listing: 41B-ReadObjectEntry.ASM. Two regions:

Region A - F1627 entry vector (121023-121032, 025-S3IRPIT) is the 8-word block pointed at by GOTAB[41], bounded strictly to the next symbol BISIZ = 121033B. Its words (061160, 116234, 061157, ...) are vector / link-cell data, not executable code - nd100-dis renders them as bogus ADD/FDV/STZ/STA instructions. The identical words appear as explicitly labelled link cells in the F1656 stub tail of MON 117B, confirming the pattern. The resident CALLPROC uses this vector to reach the worker.

Region B - ROBJE worker (55566-55725, 006-S3FS; link cells 55726-55747) is the functional body. All calls to shared file-system workers are indirect (JPL I / JMP I) through the pointer table at 55726-55747; those words are data (link cells), not code, and their resolved worker addresses are annotated in the .ASM.

  • Entry prologue (55566-55571) - 55566 STD I 140 stashes the caller's double-word; 55571 SAB 10 builds the local frame B; 55572 JPL I 135 -> 003752 is the shared resident prologue worker.
  • Locate the object block (55573-55576) - 55573 JPL I 135 -> FOBJB (55563, find-object-block, in-segment) returns the entry pointer in X; 55576 JPL I 133 -> 010500 is a resident setup worker.
  • Version / index match (55577-55637) - the caller's version and index words (B+1, B+2) are compared against the entry fields (X+1, X+2, X+3); mismatches steer into the directory-read (55613) and block-read (55653) paths.
  • Directory / index / block read (55640-55704) - 55643 JPL I 71 -> GDDRT (50121, get-directory); 55651 JPL I 64 -> RINDX (51453, read-index); 55667 JPL I 52 -> RBLOC (35531, read-block); then 55702 JPL I 42 -> 001224 (resident) and 55704 JPL I 41 -> RELBU (35476, release-buffer).
  • Copy back + exit (55705-55725) - 55705-55713 write the resolved entry words back through X into the caller's slots; 55721 STA ,B 2 stores the status word into the caller's status slot B+2; 55724 JPL I 23 -> 010506 (resident) and the paths funnel into the resident return 55715 JMP I -> 003776.

The calls to FOBJB, GDDRT, RINDX, RBLOC and RELBU are the byte-level reason ROBJE is the ReadObjectEntry worker - it walks the file-system object entry the way the manual describes.

Parameter / register contract

Reg / field Dir Meaning Verdict
entry point (vector) in 121023B = F1627, the GOTAB[41] level-14 vector VERIFIED (bytes)
entry point (worker) in 55566B = ROBJE worker entry VERIFIED (bytes)
D (double) in caller parameter, saved first (STD I 140) VERIFIED (copy); layout inferred
local frame B internal SAB 10 = 10B-word working frame VERIFIED (bytes)
T (manual) in file number (returned when the file was opened) inferred (manual MAC example)
A (manual) in address of the 64-byte object-entry receive buffer inferred (manual)
A (manual) out error number on the error return inferred (manual)
B+2 out returned status word (STA ,B 2 at 55721) VERIFIED (bytes)

The user-visible T/A register convention lives in the caller-side MON 41 wrapper and the uncarved CALLPROC frame, so the precise user-register-to-field assignment is inferred from the manual, not byte-proven here. The -1 / -10 status leaders (SAA -1, SAA -10) are VERIFIED in the code; their mapping to the SINTRAN error/status table is UNVERIFIED.

Pseudo-code (for an emulator)

See 41B-ReadObjectEntry.pseudo.c - a pseudo-C model of the handler for emulator authors. Control flow + the calls to the file-system primitives are byte-verified; the object-entry field semantics and status meanings are inferred from the call structure and the manual.

Every instruction in the model is translated per the canonical ND100-INSTRUCTION-SEMANTICS.md (bare LDA disp = mem[P+disp]; RADD CLD Sx Dy = y = x; skip-return polarity; MIN ,B 4 success bump).

Honest caveats

What is byte-proven: GOTAB[41B] = 121023B (level-14 dispatch); the F1627 block at 121023B in 025-S3IRPIT is real (8 words of vector/link-cell data); the ROBJE worker body at 55566B in 006-S3FS is real code (entry bytes 021140 146145 146131 170010 match the disassembly); and it belongs to the file-system object-entry family - it calls FOBJB, GDDRT, RINDX, RBLOC and RELBU.

What is NOT proven: the link from the F1627 vector (in 025-S3IRPIT) to the ROBJE worker (in 006-S3FS). F1627 is a vector/link-cell block, not directly-followable code; the stub->worker transfer is the resident CALLPROC/segment switch in an uncarved overlay. So the MON 41 -> ROBJE attribution rests on the ROBJE symbol name + its object-entry calls + the matching behaviour, not a followed pointer - hence MISATTRIBUTED in the strict sense. Confirming it needs a live trace: break at 121023B on a real MON 41, single-step the segment switch, and confirm P lands on ROBJE = 55566.

Region-B bound: the ROBJE worker is bounded strictly to the next FILSYS symbol WOBJE = 55750B. Code runs 55566-55725; 55726-55747 are the pointer table (link cells). Every direct branch lands inside 55566-55725.

Several link-cell contents (003752, 010500, 001224, 010506, 003776) match no FILSYS-SYMBOLS entry; their low addresses suggest resident-monitor / save-restore routines outside the file-system segment and are not resolved here.

Method: ../../../../../EXTRACTING-RESIDENT-CODE.md - dispatch reality: ../../TASK-05-mismatches.md - master map: ../../MON-CALL-INDEX.md.