MON 216B (octal) - SetObjectEntry (DWOBJ)¶
Changes the description of a file. An object entry describes each file (file name,
access rights, dates last opened for read and write, size, and more - a 64-byte
record). The normal use is GetObjectEntry to read the entry, change parts of it,
then write it back with SetObjectEntry. The caller selects the file by directory
index, user index and object index, and passes the 32-word (64-byte)
source buffer. On the ND-100 the file may live on a remote system reachable through a
COSMOS network.
Status: GOTAB dispatch head byte-proven as fall-through (GOTAB[216B] =
000000, no per-call stub); the DWOBJ worker body is real SINTRAN L bytes and reads
the entry with ROBJE (Read OBJect Entry) then writes it back with WOBJE (Write
OBJect Entry) - the write twin of ROBJE; the exact MON 216 -> worker link crosses
an uncarved kernel bridge (see Honest caveats). All
addresses/values are octal.
- Full disassembly:
216B-SetObjectEntry.ASM- the actual code (the DWOBJ worker body; there is no entry stub because the GOTAB slot is zero). - Bytes live once in the canonical segment layer:
../../segments-ref/.
Dispatch path¶
flowchart LR
A["User program<br/>MON 216B"] --> B["ENT14 level-14<br/>T = MON number"]
B --> C["GOTAB[216B] = 000000<br/>(byte-proven: fall-through)"]
C -.uncarved MFELL / CALLPROC.-> E["DWOBJ set-object-entry worker<br/>006-S3FS :104410B"]
E --> F["ROBJE read-object-entry<br/>006-S3FS :55566B"]
E --> G["WOBJE write-object-entry<br/>006-S3FS :55750B"]
class A blue
class B,C blue
class E,F,G green
classDef blue fill:#E3F2FD,stroke:#0D47A1,color:#0D47A1
classDef teal fill:#E0F7FA,stroke:#00838F,color:#00838F
classDef green fill:#E8F5E9,stroke:#2E7D32,color:#2E7D32The GOTAB slot is zero, so there is no per-call entry stub. The dashed hop
(C -> E) is the resident MFELL/CALLPROC fall-through second-level dispatch - 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. Byte offset = (addr - loadbase) in octal words x 2.
| Role | Segment (full disasm) | Addr range (octal) | Byte offset | Symbol | Verdict |
|---|---|---|---|---|---|
| GOTAB[216] dispatch word | commoncode.asm - .hex | 071451B (1 word) |
58962 | GOTAB+216 = 000000 |
VERIFIED (fall-through) |
| resident MFELL/CALLPROC bridge | - (uncarved) | - | - | CALLPROC |
UNVERIFIED |
| DWOBJ set-object-entry worker | 006-S3FS.asm - .hex | 104410B-105007B (to MRUSE) |
47632 | DWOBJ |
real bytes; link MISATTRIBUTED |
| ROBJE read-object-entry | 006-S3FS.asm - .hex | 55566B (call target) |
- | ROBJE |
called by DWOBJ (link cell 104771) - VERIFIED |
| WOBJE write-object-entry | 006-S3FS.asm - .hex | 55750B (call target) |
- | WOBJE |
called by DWOBJ (link cell 105005) - VERIFIED |
Verify by hand: grep '^104410 ' ../../segments-ref/006-S3FS/006-S3FS.hex -> byte offset 47632;
then dd if=../../../segments/006-S3FS.bin bs=1 skip=47632 count=8 | od -An -tx1 -> 22 42 cc 65 cc 59 f0 5c
(= octal 021102 146145 146131 170134 = STD I 102 / RADD CLD SL DA / RADD CLD SB DD / SAB 134, the DWOBJ entry).
The GOTAB slot itself:
dd if=../../../resident/SINTRAN-DATA_commoncode.bin bs=1 skip=58962 count=2 | od -An -tx1 -> 00 00 (= 000000, fall-through).
The WOBJE link cell: dd if=../../../segments/006-S3FS.bin bs=1 skip=48138 count=2 | od -An -tx1 -> 5b e8 (= octal 055750, the word at 105005B = the resolved WOBJE worker address); the ROBJE link cell at 104771B (byte offset 48114) holds 055566.
Instruction walkthrough¶
Full listing: 216B-SetObjectEntry.ASM. The functional body
is the DWOBJ worker; there is no F16xx stub because GOTAB[216] = 0. All calls to
shared file-system workers are indirect (JPL I / JMP I) through pointer tables
at 104512-104531 and 104770-105007. nd100-dis renders those pointer words as bogus
instructions - they are data (link cells), not code; their contents are the real
worker addresses (resolved in the .ASM).
- Entry prologue (
104410-104414) -104410 STD I 102stashes the caller's double-word parameter;104413 SAB 134builds the 134-word local frameB;104414 JPL I 77->003752is the shared resident prologue worker. - Index resolve / validate (
104415-104532) - the directory/user/object indices are validated via104417 JPL I 75->101303(CHDUO),104423 JPL I 73->053114(TUSRT),104447/104503 JPL I -> 050323(GNFLA),104462 JPL I 44->055111(GUSEN),104464 JPL I 43->054527(GMUSI),104470 JPL I 40->054130(GMFKN) and104475 JPL I 34->057771(GFIAC). Access-check failures load error70(104501/104507 SAA 70) and exit. - Read the current entry (
104617) -104617 JPL I 152->055566(ROBJE) reads the current object entry so the caller's changes can be merged; the merge loops compare fields with104647/104652/104675/104700 JPL I -> 030062(GETCH). - Write the entry back (
104756) -104756 JPL I 27->055750(WOBJE), the Write-OBJect-Entry primitive, commits the modified 64-byte entry to disk. - Finish (
104760-104765) -104760 MIN ,B 4is the success return-link bump;104764 STA ,B 2writes the result word into the caller's status slotB+2; every path funnels into the resident return104762 JMP I 24->003776.
The JPL I 152 call to ROBJE (link cell 104771 = 055566) plus the JPL I 27
call to WOBJE (link cell 105005 = 055750) are the byte-level proof that DWOBJ is
the SetObjectEntry worker: it reads the object entry, merges the caller's changes, and
writes it back - the read-modify-write the manual describes. DWOBJ (Directory Write
OBJect entry) is also the 216B short name in the manual.
Parameter / register contract¶
Manual-side names/types are from 216B_SetObjectEntry.yaml.
| Reg / field | Dir | Meaning | Verdict |
|---|---|---|---|
| entry point (worker) | in | 104410B = DWOBJ worker entry |
VERIFIED (bytes) |
D (double) |
in | caller parameter block, saved first (STD I 102) |
VERIFIED (copy); layout inferred |
local frame B |
internal | SAB 134 = 134B-word working frame |
VERIFIED (bytes) |
A (manual) |
in | address of the 32-word (64-byte) source object entry | inferred (manual MAC example) |
T (manual) |
in | INDEX: left byte = directory index, right byte = user index | inferred (manual) |
X (manual) |
in | object index (bit 15 set = remote file) | inferred (manual) |
D (manual) |
in | remote system identification (used only if remote bit set) | inferred (manual) |
A (manual) |
out | error number on the error return | inferred (manual) |
error 70 |
out | access-check error literal (SAA 70 at 104501/104507) |
VERIFIED (bytes); mapping inferred |
B+2 |
out | returned status word (STA ,B 2 at 104764) |
VERIFIED (bytes) |
The user-visible A/T/X/D register convention lives in the caller-side
MON 216 wrapper and the uncarved MFELL/CALLPROC frame, so the precise
user-register-to-field assignment is inferred from the manual, not byte-proven
here.
Pseudo-code (for an emulator)¶
See 216B-SetObjectEntry.pseudo.c - a pseudo-C
model of the handler for emulator authors. Control flow + the calls to ROBJE and WOBJE
are byte-verified; the parameter-field semantics and error-number meanings are inferred
from the call structure and the manual. Every instruction is translated per the
canonical
ND100-INSTRUCTION-SEMANTICS.md
(bare LDA disp = mem[P+disp]; RADD CLD SD DA = A = D; skip-return polarity;
MIN ,B 4 success bump).
Honest caveats¶
What is byte-proven: GOTAB[216B] = 000000 (level-14 fall-through, no per-call
vector); the DWOBJ worker body at 104410B in 006-S3FS is real code (entry bytes
021102 146145 146131 170134 match the disassembly, bounded by the next FILSYS symbol
MRUSE = 105010B); and it performs the read-modify-write - it calls ROBJE (055566B,
link cell 104771) to read and WOBJE (055750B, link cell 105005) to write.
What is NOT proven: the link from the zero GOTAB slot to the DWOBJ worker.
Because the vector is zero there is no stub to disassemble and no pointer to
dereference; dispatch drops into the resident MFELL/CALLPROC second-level path,
which lives in an uncarved overlay. So the MON 216 -> DWOBJ attribution rests on
the DWOBJ symbol name (the 216B short name) + its ROBJE/WOBJE calls + the
matching set-object-entry behaviour, not a followed pointer - hence MISATTRIBUTED
in the strict sense. Confirming the link needs a live trace: issue a real MON 216,
single-step the level-14 fall-through into the resident CALLPROC dispatch, and confirm
P lands on DWOBJ = 104410.
Region bound: the DWOBJ worker is bounded strictly to the next FILSYS symbol
MRUSE = 105010B. Several link-cell targets (003752, 020274, 001224, 003776)
sit below the 26000B segment load base; they are 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.