MON 244B (octal) - GetDirEntry (GDIEN)¶
Gets information about a directory: the directory entry (24 words / 42 bytes) is returned into the caller's buffer, together with a flag telling whether the disk has spare-track allocation. The directory index selects the entry; with bit 15 of the index register set, the entry may be read from a directory on a remote system over a COSMOS network.
Status: GOTAB dispatch head byte-proven (GOTAB[244B] = 044226B, the DFRRT
level-14 stub in 025-S3IRPIT); the GDIEN worker body is real SINTRAN L bytes and
calls the GDIRA (Get Directory Address) and GNAMA (Get Name Address)
primitives; the exact MON 244 -> worker link crosses an uncarved kernel bridge
(see Honest caveats). All addresses/values are octal.
- Full disassembly:
244B-GetDirEntry.ASM- the actual code, both regions (DFRRT entry stub + GDIEN worker with its shared body). - Bytes live once in the canonical segment layer:
../../segments-ref/.
Dispatch path¶
flowchart LR
A["User program<br/>MON 244B"] --> B["ENT14 level-14<br/>T = MON number"]
B --> C["GOTAB[244B] = 044226B<br/>(byte-proven)"]
C --> D["DFRRT entry stub<br/>025-S3IRPIT :44226B"]
D -.uncarved CALLPROC.-> E["GDIEN get-dir-entry worker<br/>006-S3FS :107111B"]
E --> F["GDIRA / GNAMA primitives<br/>006-S3FS :30225B / :30235B"]
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:#2E7D32The 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. The worker address 107111 does not occur anywhere inside
025-S3IRPIT.
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[244] dispatch word | commoncode.asm - .hex | 071477B (1 word) |
59006 | GOTAB+244 = 044226B |
VERIFIED |
| DFRRT entry stub | 025-S3IRPIT.asm - .hex | 44226B-44233B (6w) |
10540 | DFRRT |
VERIFIED |
| resident CALLPROC bridge | - (uncarved) | - | - | CALLPROC |
UNVERIFIED |
| GDIEN worker (entry + shared body) | 006-S3FS.asm - .hex | 107111B-107400B (entry 3w + body) |
50322 | GDIEN |
real bytes; link MISATTRIBUTED |
| GDIRA get-directory-address | 006-S3FS.asm - .hex | 30225B (call target) |
- | GDIRA |
called by GDIEN (link cell 107244) - VERIFIED |
| GNAMA get-name-address | 006-S3FS.asm - .hex | 30235B (call target) |
- | GNAMA |
called by GDIEN (link cell 107246) - VERIFIED |
Verify by hand: grep '^44226 ' ../../segments-ref/025-S3IRPIT/025-S3IRPIT.hex -> byte offset 10540;
then dd if=../../../segments/025-S3IRPIT.bin bs=1 skip=10540 count=8 | od -An -tx1 -> c9 00 a8 15 a8 14 ba 1a
(= octal 144400 124025 124024 135032 = RAND 0 0 / JMP 25 / JMP 24 / JPL I 32, the DFRRT stub head).
The GOTAB slot itself:
dd if=../../../resident/SINTRAN-DATA_commoncode.bin bs=1 skip=59006 count=2 | od -An -tx1 -> 48 96 (big-endian word = 044226B).
The GDIEN worker entry:
dd if=../../../segments/006-S3FS.bin bs=1 skip=50322 count=8 | od -An -tx1 -> f8 10 f8 38 a8 03 f8 90
(= octal 174020 174070 124003 174220 = BSET ZRO SSK / BSET ZRO SSM / JMP 3 / BSET ONE SSK, the GDIEN entry followed by the sibling GNAEN entry).
Instruction walkthrough¶
Full listing: 244B-GetDirEntry.ASM. The functional body is
the GDIEN worker (region B); the DFRRT stub (region A) is the level-14 entry.
Region A - DFRRT stub (44226-44233) is the compact level-14 entry pointed at
by GOTAB[244]. It clears A (44226 RAND 0 0) and its direct branches leave the
stub - 44227/44230/44233 JMP -> 44254 reach shared level-14 tail code in the same
segment, and 44231/44232 JPL I 32 -> 44263/44264 call shared level-14 routines.
None of these reach the GDIEN body (that transfer is the uncarved CALLPROC hop);
107111 never appears in 025-S3IRPIT.
Region B - GDIEN worker (107111 + shared body 107116-107400) is the
directory-entry body. GDIEN itself is only 3 words: it sets two skip flags -
107111 BSET ZRO SSK (SSK=0, directory entry rather than name) and
107112 BSET ZRO SSM (SSM=0, get rather than write) - then 107113 JMP 3 ->
107116 joins a body shared with the sibling entries WDIEN (107106, Write Dir
Entry, SSM=1) and GNAEN (107114, Get Name Entry, SSK=1). The body latches the
two flags into B+104/B+105 (107123-107136) and dispatches on them.
- Entry prologue (
107116-107122) -107116 STD I 112stashes the caller's double-word parameter;107121 SAB 106builds the 106-word local frameB;107122 JPL I 107->003752is the shared resident prologue worker. - Get-entry path (
107211-107247) - with SSK=0 the body takes107213 JPL I 31->030225(GDIRA, get directory address); the SSK=1 sibling path uses107217 JPL I 27->030235(GNAMA, get name address). A range/validity failure loads error174(107226 SAA 174) and exits. - Format + finish (
107250-107365) - the read path formats the directory entry into the caller's buffer via resident/SUCPB/GNFLAworkers; the write sibling path uses107356 JPL I 21->047716(WDIRE, write dir entry). The store-status point107364 STA ,B 2writes the result word into the caller's status slotB+2; every path funnels into the resident return107362 JMP I 16->003776.
The JPL I 31 call to GDIRA (link cell 107244 = 030225) plus the JPL I 27
call to GNAMA (link cell 107246 = 030235) are the byte-level proof that GDIEN
is the GetDirEntry worker - it drives the directory-address primitives, and its
short name GDIEN matches the manual's GetDirEntry.
Parameter / register contract¶
| Reg / field | Dir | Meaning | Verdict |
|---|---|---|---|
| entry point (stub) | in | 044226B = DFRRT, the GOTAB[244] level-14 stub |
VERIFIED (bytes) |
| entry point (worker) | in | 107111B = GDIEN worker entry |
VERIFIED (bytes) |
SSK (skip flag) |
internal | 0 at GDIEN entry = directory entry (not name); latched to B+105 |
VERIFIED (bytes) |
SSM (skip flag) |
internal | 0 at GDIEN entry = get (not write); latched to B+104 |
VERIFIED (bytes) |
D (double) |
in | caller parameter block, saved first (STD I 112) |
VERIFIED (copy); layout inferred |
local frame B |
internal | SAB 106 = 106-word working frame |
VERIFIED (bytes) |
T (manual) |
in | directory index (bit 15 in X set -> remote system id in D) |
inferred (manual MAC example) |
X (manual) |
in | address of buffer receiving the 24-word directory entry | inferred (manual MAC example) |
D (manual) |
in | remote system identification (only if bit 15 in X set) |
inferred (manual) |
A (manual) |
out | normal return: 1/5 = spare-track allocation, 3 = none; error return: error number |
inferred (manual) |
B+2 |
out | returned status word (STA ,B 2 at 107364) |
VERIFIED (bytes) |
error 174 |
out | address/validity error literal (SAA 174 at 107226) |
VERIFIED (bytes); mapping inferred |
The user-visible T/X/D register convention lives in the caller-side MON 244
wrapper and the uncarved CALLPROC frame, so the precise
user-register-to-field assignment is inferred from the manual
(244B_GetDirEntry.yaml),
not byte-proven here.
Pseudo-code (for an emulator)¶
See 244B-GetDirEntry.pseudo.c - a pseudo-C model
of the handler for emulator authors. Control flow + the calls to the GDIRA/GNAMA
primitives are byte-verified; the parameter-field semantics and error-number
meanings are inferred from the call structure and the manual.
Every instruction in the .pseudo.c is translated against the canonical
ND100-INSTRUCTION-SEMANTICS.md
(bare LDx/LDT/AND disp = P-relative mem[P+disp], not literals; SKP/BSKP skip
polarity; RADD CLD SD DA = A = D; T/X transfers = physical EL).
Honest caveats¶
What is byte-proven: GOTAB[244B] = 044226B (level-14 dispatch); the DFRRT
stub at 044226B in 025-S3IRPIT is real code (head bytes 144400 124025 124024
135032 match the disassembly); the GDIEN worker at 107111B in 006-S3FS is
real code (entry bytes 174020 174070 124003 match the disassembly); GDIEN is a
3-word flag-setting entry that joins a body shared with WDIEN/GNAEN; and it
belongs to the directory-entry family - it calls GDIRA (030225B, link cell
107244) and GNAMA (030235B, link cell 107246).
What is NOT proven: the link from the DFRRT stub (in 025-S3IRPIT) to the
GDIEN worker (in 006-S3FS). The value 107111 occurs zero times as a target
inside the DFRRT stub; the stub's own direct branches stay in 025-S3IRPIT (to
shared level-14 tail code at 44254B and sibling routines at 44263B/44264B),
and the stub->worker transfer is the resident CALLPROC/segment switch in an
uncarved overlay. So the MON 244 -> GDIEN attribution rests on the GDIEN
symbol name (GetDirEntry) + its calls to GDIRA/GNAMA + the matching
directory-entry behaviour, not a followed pointer - hence MISATTRIBUTED in the
strict sense. The DFRRT symbol name does not itself resemble GetDirEntry, which
is expected: the stub is the family's shared level-14 dispatch head, not a named
per-call worker. Confirming the link needs a live trace: break at 44226B on a
real MON 244, single-step the segment switch, and confirm P lands on
GDIEN = 107111.
Region-B bound: the GDIEN worker's shared body is bounded strictly to the next
symbol RESDI = 107401B. The sibling entries WDIEN = 107106B and
GNAEN = 107114B are the Write-Dir-Entry and Get-Name-Entry calls' entries; they
set different SSM/SSK flags and share this same body - they are shown for
context only and are not the GetDirEntry body.
Several link-cell contents (003752, 020274, 001224, 010500, 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.