SPREL

MON 60 subfunction 044B (octal) = 0x24 = 36 decimal. NPL purpose (authoritative, 5P-P2-MON60.NPL, via SUBFUNCTION-TABLE.md): RELEASE ND-500 CPU/SYSTEM FROM SPECIAL USE, server handler ISREL. Client name (yaml 60B_N500M.yaml): SPREL, "Release after special use", params (none).

All addresses are OCTAL ND-100 word addresses, BANK 1, base 0. Source: SINTRAN/ND500/nd-500-mon/nd-500-mon-j04.prog.asm

Thunk (PROVEN)

146472 SAA 44 / 146473 JMP I 1 / 146474 146244 (gateway). Verified from bytes.

Call site (PROVEN)

Call site	Enclosing routine	Resolution	Kind
007505 JPL I 120	interpreter ENTER 002662 (fs 000331=217), case 007477-007507	ptr 007625=146472	interpreter case

Parameter block

SPREL takes no parameters (yaml (none)). 007477 JMP 6 jumps directly to the call at 007505 with no ,X-slot stores in between - PROVEN by inspection.

Skip / error handling

• ERROR (callsite+1): 007506 JPL -6 -> 007500 (local error-handler code block).
• SUCCESS (callsite+2): 007507 JMP I -111 -> ptr 007376 = 010613 (command loop).

Unknown / inferred

• INFERRED (role): 007500 is this case's local error handler; 010613 is the interpreter command loop (entry addresses PROVEN, internals not carved).
• SPRES (043B, case 007450-007476) and SPREL sit adjacently in the interpreter; SPRES reserves for special use and SPREL releases it. See 043B-SPRES.