TASK-04 — File-system internals (S3FS)

Do the shared setup first.

Load

Program	File	Base	Symbols
S3FS	segments\006-S3FS.bin	0x2C00 (oct 26000)	re\006-S3FS.ghidra-symbols.txt

Verify: 0x568F (RUSPW) = STZ ,B 0; 0x46FE (DPASS) = SWAP SD DX.

Goal

Map the SINTRAN file-system segment beyond login (TASK-01 covers password/login): directory lookup, file open/close, page/block allocation, and the on-disk directory/object structures the code manipulates.

Context

• S3FS (segment 6) is the file-system code segment; S3SFS (seg 12) is its save copy; S3RFAC (seg 22, 022-S3RFAC.bin, base 0x2C00) is remote file access.
• The NPL file-system SOURCE is NOT in the repo (only FILSYS-SYMBOLS), so this segment IS the primary source. Symbol table: FILSYS-SYMBOLS.SYMB.TXT (L07).
• Cross-check on-disk structures with norskdata-ndfs (it already models the NDFS directory/user/object entries): ~/repos/norskdata-ndfs/ndfs-c/include/ndfs/.
• Repo docs: ..\..\SINTRAN\OS\15-DISK-IO-SUBSYSTEM.md, ..\..\SINTRAN Structures\SINTRAN-STRUCTURES.md.

Steps

1. From the FILSYS-SYMBOLS labels, group routines: directory (ENTER, RUSER, RUSPW, object lookup), open/close, allocation (bit-file / page allocation), and the MON-call entry points that land here (RFILE/WFILE/OPEN etc.).
2. Recover the on-disk object/directory entry layout as the code reads/writes it; reconcile with the norskdata-ndfs structs (confirm or correct field offsets).
3. Note the MON 0347 (NUCL) usage seen in DPASS and elsewhere.

Deliverable

Write versions\L-VSX-500\re\TASK-04-results.md: a routine map (name → addr hex+oct → function), the directory/object structure layout with field offsets, and any discrepancies with norskdata-ndfs, VERIFIED/UNCERTAIN.