Installing the ND-500 Linkage-Loader (NLL) and the Backup System¶

Products: - ND-500 Linkage-Loader H02, floppy 210319H02-XX-01D - article number ND-210319 (confirmed by the ND LINKER product's own PI sheet, which names it explicitly as "LINKAGE LOADER (ND 210319)"; the older base article ND-10319 is a separate, earlier-generation PI sheet for the same product family, same pattern as ND-10337/ND-210337 elsewhere in this catalog) - Backup System I04 (program version I02), floppy 210337I04-XX-01D - HARD PREREQUISITE for the NLL install

Source: verified live installation session on SINTRAN with ND-500/5000 MONITOR Version J04 (88.6.16 / 88.8.17), run in the RetroCore ND-100 emulator, session date 2026-07-19 (emulated system clock 19-JUL-98). Everything below is observed behavior from that session log, not manual text.

1. Symptoms Before Installation (Why You Are Here)¶

On a system without NLL installed:

N500: ND-500-LINKAGE-LOADER
TOO LONG PARAMETER

@ND-500-LINKAGE-LOADER
"ND-500-LINKAGE-LOADER"
TOO LONG PARAMETER

N500: LINKAGE-LOADER
DESCRIPTION FILE ERROR: DESCRIPTION-FILE
NO SUCH FILE NAME

Interpretation of the observed errors:

TOO LONG PARAMETER: with no LINKAGE-LOADER command/standard-domain present, the name is treated as a domain name, and domain names are limited to 16 characters - "ND-500-LINKAGE-LOADER" is 21. The error is therefore about the NAME LENGTH, not about the product missing, which makes it a misleading first symptom.
LINKAGE-LOADER is the correct short form inside the monitor, and its error is the honest one: there is no DESCRIPTION-FILE:DESC yet, i.e. NLL has never been installed/used for this user.

2. Prerequisites (Do These FIRST)¶

The NLL installer will fail or abort without these. All were discovered the hard way in the session:

User DOMAIN-USER must exist with disk space. The installer's module 1 defaults to placing the NLL domain on user DOMAIN-USER, but does NOT create it:
```
@CREATE-USER DOMAIN-USER
@GIVE-USER-SPACE DOMAIN-USER, 1000    (1000 pages used in the session)
```
User UTILITY must exist with at least 177 free pages (the Backup System installer states the 177-page requirement explicitly; it found only 2 and terminated):
```
@GIVE-USER-SPACE UTILITY, 500
```

The Backup System must be installed BEFORE the Linkage-Loader. NLL's module 3 environment check fails hard otherwise:

:::  ERROR  :::
The subsystem BACKUP-SYSTEM is not found.
:::  WARNING  :::
The environment is NOT OK. You cannot COPY before the environment is ok!

Mount the floppies. In the session (RetroCore emulator: Ctrl-E to the debugger, attach fd0/fd1 <image>, cont), then in SINTRAN:
```
@ENTER-DIRECTORY
DIRECTORY NAME: (empty - taken from the floppy label)
DEVICE NAME: FLOPPY-DISC-1
DEVICE UNIT: 0            (or 1 for the second drive)
```
Verify with @LIST-DIRECTORIES-ENTERED (the session used the DIR abbreviation) - the floppy shows up as e.g. DIR INDEX 40 : FLOPPY-DISC-1 UNIT 0 : 210319H02-XX-01D.

3. Installing the Backup System (210337I04-XX-01D)¶

Floppy contents:

(210337I04-XX-01D:FLOPPY-USER)INST-BASY-I04:PROG      <- the installer
(210337I04-XX-01D:FLOPPY-USER)RESERVE-SYSTEM:MODE
(210337I04-XX-01D:FLOPPY-USER)RESERVE-SYSTEM:BATC
(210337I04-XX-01D:FLOPPY-USER)BACKUP-SERV-I02:PROG
(210337I04-XX-01D:FLOPPY-USER)BACKUP-SYS-I02:PROG
(210337I04-XX-01D:FLOPPY-USER)UE-ERMSG-EN-C05:ERR

Run:

@(210337I04-XX-01D:FLOPPY-USER)INST-BASY-I04:PROG

Question-and-answer flow (observed):

Delete previous version ... (Y/N) - Y/N answer.
Please specify which user you want the files ... copied to (default: UTILITY) - this prompt wants a USER NAME. Press plain CR to accept UTILITY. See gotcha G6 below - answering y here creates a demand for a user literally named y and the installer terminates.
Should the BACKUP-SYSTEM be dumped reentrant (Y/N) ? - answered Y. The installer itself warns: "The message: NO SUCH FILE NAME is ok!" - the subsequent @DELETE-REENTRANT BACKUP prints NO SUCH NAME on a first-time install and that is EXPECTED, not a failure.

The installer then copies the files (RESERVE-SYSTEM to SYSTEM, BACKUP-SERV/BACKUP-SYS to UTILITY, error file to SYSTEM), does @DUMP-PROGRAM-REENTRANT BACKUP-SYSTEM-I (UTILITY)BACKUP-SYS-I, and runs a MODE job (BACKUP-LOAD-I:MODE) that loads the DMA-Server onto a segment called DMASEG (output logged to BACKUP-LOAD-I:OUT).

Post-install steps the installer tells you NOT to forget (they do not survive a cold start otherwise):

Append to the DUMP-REENTRANT file on user SYSTEM:
  @DUMP-PROGRAM-REENTRANT BACKUP-SYSTEM-I, (UTILITY)BACKUP-SYS-I02:PROG

Append (SYSTEM)BACKUP-LOAD-I:MODE to the HENT-MODE file on user SYSTEM

It also resets termination handling to blanks and tells you how to restore it (@DEFINE-TERMINATION-HANDLING, B, NO TERMINATION DEFINED!).

Verify:

@LIST-REENTRANT
   START RESTART SEGMENT   NAME
      0B      1B    130B   BACKUP-SYSTEM-I

@BACKUP-SYSTEM
BACKUP-SYSTEM / I02  870827
Ba-sy:

4. Installing the Linkage-Loader (210319H02-XX-01D)¶

Floppy contents:

(210319H02-XX-01D:FLOPPY-USER)IN-NLL-XX-H02:PROG      <- the installer
(210319H02-XX-01D:FLOPPY-USER)IN-NLL-XX-H02:XCOM      <- installer data
(210319H02-XX-01D:FLOPPY-USER)IN-NLL-XX-H02:INIT
(210319H02-XX-01D:FLOPPY-USER)DESCRIPTION-FILE:DESC
(210319H02-XX-01D:FLOPPY-USER)LINKAGE-LOAD-H02:PSEG   <- the NLL domain itself
(210319H02-XX-01D:FLOPPY-USER)LINKAGE-LOAD-H02:DSEG
(210319H02-XX-01D:FLOPPY-USER)LINKAGE-LOAD-H02:LINK
(210319H02-XX-01D:FLOPPY-USER)LINKAGE-LOAD-H02:UTIL

Run (abbreviated spec @(21:fl)IN-NLL:PROG worked while only one floppy directory was entered; use the full spec to be safe):

@(210319H02-XX-01D:FLOPPY-USER)IN-NLL-XX-H02:PROG

The installer copies itself and its :XCOM data to SYSTEM (deleted again on finish/abort), creates IN-NLL-XX-H02:INST on SYSTEM (your answers, reused as defaults next run), creates a log IN-NLL-XX-H02:LOGG on SYSTEM (delete manually after success), disables Escape, and enables USER-BREAK / FATAL-ERROR termination handling ("messages which are not error messages").

It presents a 5-module main menu that MUST be executed in order 1 to 5:

1  Get start information       (which users get the domain / utility files:
                                defaults DOMAIN-USER and UTILITY)
2  Delete product files        (previous/current versions; strict YES/NO answers)
3  Check environment and resources
                               (SINTRAN environment, BACKUP-SYSTEM present,
                                free pages + object entries on SYSTEM,
                                DOMAIN-USER, UTILITY)
4  Copy product files          (only allowed after module 3 says environment OK)
5  Exit program

Module 4 (observed):

Copies LINKAGE-LOAD-H02:UTIL to user UTILITY
Copies the domain LINKAGE-LOAD-H02 to user DOMAIN-USER
Defines the domain as standard domain LINKAGE-LOADER
Then prompts to remove the floppy

Post-install step the installer tells you to do (standard domains do NOT survive a cold start):

Append to the ND500-HENT file on user SYSTEM:

@ND-500-MONITOR
DEFINE-STANDARD-DOMAIN LINKAGE-LOADER (DOMAIN-USER)LINKAGE-LOAD-H02

On module 5 exit it asks whether to copy IN-NLL-XX-H02:INST back to the floppy (default N).

After this, N500: LINKAGE-LOADER (and per the manual @ND-500-LINKAGE-LOADER) resolves to the standard domain.

4a-VERIFIED. G12 Recovery That Actually Works - Four File Copies, No ND-500¶

Status: MEASURED END TO END, 2026-08-01, in the RetroCore boot harness (NllInstaller_RunFiveModules_Capture). This supersedes section 4a below for practical purposes: section 4a needs RECOVER-DOMAIN, which starts the ND-500 swapper; this does not touch the ND-500 at all.

Run the installer normally (section 4). It will report INSTALLATION - FINISHED while having copied no domain - that is G12. Then repair it by hand.

The floppy is a complete NLL installation under FLOPPY-USER, so the whole repair is four ordinary file copies onto the user who should own the loader (SYSTEM here - domains on SYSTEM are found automatically for every user):

@ENTER-DIRECTORY                      <- module 4 RELEASED the floppy; enter it again
DIRECTORY NAME:                       (empty CR - taken from the label)
DEVICE NAME: FLOPPY-DISC-1
DEVICE UNIT: 0

@COP-FIL "DESCRIPTION-FILE:DESC",(210319H02:FL)DESCRIPTION-FILE:DESC
@COP-FIL "LINKAGE-LOAD-H02:PSEG",(210319H02:FL)LINKAGE-LOAD-H02:PSEG
@COP-FIL "LINKAGE-LOAD-H02:DSEG",(210319H02:FL)LINKAGE-LOAD-H02:DSEG
@COP-FIL "LINKAGE-LOAD-H02:LINK",(210319H02:FL)LINKAGE-LOAD-H02:LINK

Then, inside the monitor:

ND-5000: LIST-DOMAIN
Domain no.   0: SCRATCH-DOMAIN
Domain no.   1: LINKAGE-LOAD-H02.......................SA:   26000006721

ND-5000: DEFINE-STANDARD-DOMAIN LINKAGE-LOADER LINKAGE-LOAD-H02
ND-5000: LINKAGE-LOADER
> Loading Control Store
> Loading Swapper
> Allocating memory - 7110B pages

The domain is registered WITH a start address and the standard domain resolves, which settles an open question from section 4a: the floppy's description file does NOT hard-code its own directory, so plain COPY-FILE is sufficient and COPY-DOMAIN is not required.

[CORRECTION 2026-08-28 - the bytes contradict the bolded claim above. IT DOES hard-code its directory.] Decoding the description file's records (0xC0 records from 0x4000, name at +0x04 terminated by 0x27) shows every entry carrying the prefix explicitly:
(210319H02:FLOPPY-USER)SCRATCH-SEG-01      PSEG 5        DSEG 1029
(210319H02:FLOPPY-USER)LINKAGE-LOAD-H02    PSEG 123989   DSEG 2184977
The sizes match the shipped files byte for byte, so that is the right file being read correctly.

CONFIRMED FROM THE RUNNING MACHINE, not just from the file. A live capture on 2026-08-28 placed the domain with the floppy directory entered, and SINTRAN's own physical segment table reported the segments still carrying that prefix:
Phys. segment no.:.... 13B  (SYSTEM name) (210319H02-XX-01D:FLOPPY-USER)LINKAGE-LOAD-H02:PSEG   75B pages
Phys. segment no.:.... 14B  (SYSTEM name) (210319H02-XX-01D:FLOPPY-USER)LINKAGE-LOAD-H02:DSEG 2053B pages
75B = 61 and 2053B = 1067 pages, matching 123989 and 2184977 bytes at 2048 B/page. So the prefix is not decorative - it is what the segment lookup uses.

WHY THE ORIGINAL CLAIM LOOKED TRUE: registration succeeds either way. The prefix is not consulted until the :PSEG/:DSEG opens happen, so a plain COPY-FILE onto SYSTEM produces a domain that RESOLVES and then fails later, at file-open time, pointing at a directory that does not exist on the pack. "It registered" is not evidence that the copy was sufficient.

THE CONSEQUENCE IS THE OPPOSITE OF MORE COPYING. Because the prefix IS honoured, the working route is to satisfy it rather than to rewrite it - enter the floppy directory and place from there:
@ENTER-DIRECTORY 210319H02,FLOPPY-DISC-1,0
@LIST-DIRECTORIES-ENTERED,,TERMINAL      (expect: DIR INDEX 40 : FLOPPY-DISC-1 UNIT 0 : 210319H02-XX-01D)
N500: PLACE-DOMAIN (210319H02:FLOPPY-USER)LINKAGE-LOAD-H02
That leaves the pack untouched. It also avoids a real hazard with the COPY-FILE route: there is one DESCRIPTION-FILE per user, and the copy on BIGDISK0-L-DOMS.IMG currently belongs to LED (it registers LED-B03 and SCRATCH-SEG-01 from floppy 211160B03). Copying the loader's description file onto SYSTEM overwrites LED's registration - the two products compete for the same slot.

Three command-syntax traps, each of which cost a full run¶

Quote the DESTINATION only, never the SOURCE. A quoted name means "create this file", so quoting the source asks SINTRAN to create a file on the floppy and it answers NOT DIRECTORY ACCESS - which reads exactly like a directory-permissions problem and is not one. A @LIST-FILES on the same floppy in the same breath succeeded; that probe is what disproved the directory theory.
The command buffer cuts at about 72 characters, answering TOO LONG STRING, with the truncated tail running into the next command in the transcript. Drop the destination user (an unprefixed name lands on the current user) and abbreviate the source directory.
Module 4 releases the floppy directory ("Remove floppy ... from station 1 unit 0"). Copies afterwards fail with DIRECTORY NOT ENTERED until it is entered again.

SOURCE EMPTY on the :LINK copy is EXPECTED - that file is 0 bytes on the distribution floppy.

What still blocks RUNNING it (not an install problem)¶

[UPDATE 2026-08-31 - THIS SECTION IS OUT OF DATE. THE LOADER NOW RUNS.]

The paragraph below records the protect violation in 5SWAP as "a pre-existing emulator-side defect". It is no longer reproducible, and the two things that were actually wrong were BOTH outside the emulator:

The swap file needs DEFINING on every boot, not just creating. ND-500-MON says a DEFINE-SWAP-FILE definition "will survive a warm start, but NOT a cold start", and the harness cold-starts every run. The pack already CARRIED a swap file ((SYSTEM)SWAP-FILE:DATA); the file was never missing, the definition was.

The test harness attached no ND-500 CPU before PLACE-DOMAIN. The harness installs its ProcessHost bridge just before RUN, on the assumption that the engine "is only needed from RUN onward". That is false for PLACE-DOMAIN, which LOADS AND STARTS THE SWAPPER as part of placement. With no CPU the swapper start was answered with an all-zero stop record and the monitor rendered trap number 0 as NOT KNOWN TRAP at program address: 0 0B.

With both fixed, the sequence completes:
N500: place-domain (210319H02-XX-01D:FLOPPY-USER)LINKAGE-LOAD-H02
> Loading Control Store
> Loading Swapper
> Allocating memory - 7116B pages
N500: run
ND-Linkage-Loader -  H.02   3. March      1988 Time: 16:48
Nll:
COPY-DOMAIN also works from that prompt. Note it answers FILE ALREADY EXISTS - FILE, not domain - if the old file-copied :PSEG/:DSEG/:UTIL are still on SYSTEM; it creates :LINK and then aborts, leaving an empty :LINK behind. Delete the leftovers first.

Beware LIST-DOMAIN at the Nll: prompt: it describes the description file the LOADER is using - the floppy it was placed from - not the pack being repaired. It printed identical before/after lists across two runs; the exported pack read with ndfs is what settled it.

Detail: E:\Dev\Ronny\ND500UC\docs\ND500-LINKAGE-LOADER-WORKING-2026-08-31.md.

Starting the loader needs a defined ND-500 swap file (without one: SWAPPING SPACE NOT AVAILABLE). With one defined, the start reaches > Allocating memory - 7110B pages and then takes a protect violation in shadow process 5SWAP. That signature is byte-identical to the one seen long before this product was installed, so it is a pre-existing emulator-side defect, independent of the installation.

4a. Manual Installation Straight From the Floppy (Recovery Path)¶

Use this when the installer's module 4 claimed success but @LIST-FILES (DOMAIN-USER) is empty (gotcha G12). The trick: the floppy itself is a complete, runnable NLL installation under FLOPPY-USER (description file + :PSEG/:DSEG/:LINK), so NLL can be started directly from the floppy and then told to copy ITSELF to the local disk with its own COPY-DOMAIN command.

Status: manual-derived (commands verified against ND-60.136.04A sections 6.1.8, 8.1.1, 8.1.2); pending live confirmation.

Step by step, logged in as the user who should OWN the loader (SYSTEM recommended - domains on SYSTEM are found automatically for every user, no standard domain needed):

1. Mount the floppy (RetroCore: Ctrl-E, then)
     attach fd0 "C:\Users\ronny\Downloads\ND-disk-00042.img"
     cont

2. Enter the floppy directory (skip if already entered - check with the DIR listing):
   @ENTER-DIRECTORY
   DIRECTORY NAME:               (empty CR - taken from the floppy label)
   DEVICE NAME: FLOPPY-DISC-1
   DEVICE UNIT: 0

3. Sanity check - the domain files must be visible:
   @LIST-FILES (210319H02-XX-01D:FLOPPY-USER)LINKAGE

4. Start NLL directly from the floppy:
   @ND-500
   N500: RECOVER-DOMAIN (210319H02-XX-01D:FLOPPY-USER)LINKAGE-LOAD-H02
   (expect the NLL: prompt - NLL is now running from the floppy)

5. Copy the whole domain to the current user
   (double quotes on the destination = create new domain; no user prefix
    allowed on the destination - it always lands on the CURRENT user):
   NLL: COPY-DOMAIN (210319H02-XX-01D:FLOPPY-USER)LINKAGE-LOAD-H02,"LINKAGE-LOAD-H02"

6. Verify and leave:
   NLL: LIST-DOMAIN
   NLL: EXIT

7. Test the local copy (no floppy involvement anymore):
   N500: LINKAGE-LOAD-H02
   (expect the NLL: prompt again; NLL: EXIT to leave)

8. Optional speed-up, as user SYSTEM (and append the same lines to the
   ND500-HENT file on SYSTEM so it survives a cold start):
   N500: DEFINE-STANDARD-DOMAIN LINKAGE-LOADER LINKAGE-LOAD-H02
   (prefix the domain name with (<owner>) if the owner is not SYSTEM)

9. Release the floppy:
   @RELEASE-DIRECTORY 210319H02-XX-01D

If a step fails:

NOT REQUIRED ACCESS TO SEGMENT at step 4 -> file access on the floppy's segment files; fix with @SET-FILE-ACCESS on (210319H02-XX-01D:FLOPPY-USER)LINKAGE-LOAD-H02:PSEG and :DSEG (RW for :DSEG), then retry. Documented in ND-60.136.04A chapter 14.
NO SUCH (AMBIGUOUS) DOMAIN ON THE SPECIFIED USER at step 4 -> the domain name in the floppy's description file differs; run N500: LIST-DOMAIN (210319H02-XX-01D:FLOPPY-USER) to see the real name and use that.
DOMAIN ALREADY EXISTS-type error at step 5 -> a half-created local domain exists; drop the double quotes to overwrite it, or DELETE-DOMAIN it first (from NLL, no domain set).

5. Pain Points and Gotchas (All Observed)¶

G1 - The pre-install error is misleading. @ND-500-LINKAGE-LOADER fails with TOO LONG PARAMETER (name > 16 chars treated as a domain name), which says nothing about the product being missing. The informative probe is N500: LINKAGE-LOADER -> DESCRIPTION FILE ERROR ... NO SUCH FILE NAME.

G2 - Missing default user aborts the whole installer. Module 1's default DOMAIN-USER does not exist on a fresh system; the installer prints User DOMAIN-USER does not exist!, re-prompts once, and then aborts the entire program (YOU HAVE ABORTED THE PROGRAM) rather than letting you retry. Create DOMAIN-USER (with pages) before starting.

G3 - The abort/exit path itself loops. After an abort, the Do you want to copy IN-NLL-XX-H02:INST to floppy number 1? question came back three times (Escape at the prompt re-aborts into the same question). Answer it with N and CR to actually get out.

G4 - Installer state is not persisted between runs. After the Backup System detour and a fresh start of the NLL installer, selecting module 3 directly gives You have to run module 1 before starting this module! - module 1 must be re-run every session, even if only to CR through the defaults.

G5 - Backup System page requirement. UTILITY needs >= 177 free pages; with only 2 the installer terminates immediately with an explicit message. @GIVE-USER-SPACE UTILITY, 500 fixed it.

G6 - "default:" prompts are NOT yes/no prompts. The Backup System question Please specify which user ... (default: UTILITY): was answered y - the installer took y as a literal user name (Illegal user name ... User 'y' don't exist) and terminated. Rule of thumb from this session: CR accepts the default; only type text if you mean it as the value. Conversely, module 2's questions insist on real YES/NO (This is a YES/NO question!).

G7 - Expected "errors" that are not errors. The Backup System install legitimately prints NO SUCH FILE NAME (during DELETE-REENTRANT of a version that was never installed) and warns beforehand that this is OK. The termination-handling ENABLED/DISABLED banners are also informational.

G8 - Directory-prefix abbreviation quirks. @LIST-FILES (21:fl) worked with one floppy entered; later (21-fl) gave NO SUCH USER NAME IN MAIN DIRECTORY (hyphen instead of colon) and (21-:fl) worked. With BOTH product floppies entered, the second one needed a longer prefix ((21033:fl)). Also @LIST-DIRECTORIES-ENTERED takes a directory NAME parameter - giving it (21:fl) produces ILLEGAL CHARACTER IN PARAMETER; parenthesized specs belong to FILE parameters only.

G9 - Three manual persistence steps, or a cold start loses the install. Collected from both installers: 1. @DUMP-PROGRAM-REENTRANT BACKUP-SYSTEM-I, (UTILITY)BACKUP-SYS-I02:PROG -> append to the DUMP-REENTRANT file on SYSTEM. 2. (SYSTEM)BACKUP-LOAD-I:MODE -> append to the HENT-MODE file on SYSTEM. 3. @ND-500-MONITOR + DEFINE-STANDARD-DOMAIN LINKAGE-LOADER (DOMAIN-USER)LINKAGE-LOAD-H02 -> append to the ND500-HENT file on SYSTEM.

G12 - CONFIRMED: module 4's domain copy can fail SILENTLY. In this session the installer printed Copying the domain: LINKAGE-LOAD-H02 to user DOMAIN-USER, continued to COPYING FINISHED and Defining the domain: LINKAGE-LOADER as a standard-domain with no error - yet afterwards @LIST-FILES (DOMAIN-USER) showed NO files at all (verified 2026-07-19). The "Copying the domain" message is printed BEFORE the work and the installer does not check the result. Always verify module 4 with @LIST-FILES (DOMAIN-USER) before trusting INSTALLATION FINISHED.

Root cause is NOT determined from the log (no error was emitted). Plausible-but-unverified candidates: (a) a domain copy needs the DESTINATION user's DESCRIPTION-FILE:DESC, which cannot exist before NLL has ever run for that user (chicken-and-egg), and NLL's own COPY-DOMAIN can only target the CURRENT user (manual ND-60.136.04A sections 6.1.1, 6.1.8) while the installer ran as SYSTEM; (b) an access/rights problem on the freshly created DOMAIN-USER. Marked ASSUMPTION until the installer internals are analyzed.

G12 recovery - run NLL directly from the distribution floppy and let it install itself. The floppy is a complete NLL installation under FLOPPY-USER (description file + all three segment files). With the floppy entered as a directory, log in as the user who should OWN the loader (DOMAIN-USER per installer convention, or SYSTEM - domains on SYSTEM are found automatically for all users per the RECOVER-DOMAIN search order, section 8.1.2):

@ND-500
N500: RECOVER-DOMAIN (210319H02-XX-01D:FLOPPY-USER)LINKAGE-LOAD-H02
NLL: COPY-DOMAIN (210319H02-XX-01D:FLOPPY-USER)LINKAGE-LOAD-H02, "LINKAGE-LOAD-H02"
NLL: EXIT

Entering NLL creates the current user's description file if missing; COPY-DOMAIN with a quoted destination creates the domain and copies every segment (section 6.1.8). Then, as SYSTEM:

Access rights (what the manual actually requires): NO friend relationship is needed - cross-user domain use is governed by ordinary SINTRAN file access on the segment files. Per the Monitor error NOT REQUIRED ACCESS TO SEGMENT (ND-60.136.04A chapter 14): the default access set by NLL's EXIT lets other users EXECUTE a program segment (not modify it), and if the data segment swaps from its original file, other users need RW on the :DSEG - fixed with SINTRAN @SET-FILE-ACCESS. If the floppy recovery fails with that error, set access on the floppy's LINKAGE-LOAD-H02:PSEG/:DSEG and retry. Cross-user DELETION of domains/segments is flat-out illegal regardless of access (NOT DELETE ACCESS, chapter 13), and the manual documents no way for NLL to CREATE a domain under another user (SET-DOMAIN/COPY-DOMAIN always target the current user) - which is why running the copy AS the owning user is the clean path, and how the installer's cross-user "copy the domain" step remains undocumented magic.

N500: DEFINE-STANDARD-DOMAIN LINKAGE-LOADER (<owner>)LINKAGE-LOAD-H02

and append that (plus the @ND-500-MONITOR line) to ND500-HENT for cold-start survival. The user-prefixed RECOVER-DOMAIN form is per manual section 8.1.1 ("syntax is equal to the file system syntax"); running NLL off the floppy this way is the manual-derived recovery, status: pending live verification.

G10 - Cleanup is manual. (SYSTEM)IN-NLL-XX-H02:LOGG (the installation log) must be deleted by hand after a successful install; the :PROG/:XCOM copies clean themselves up.

G11a - The "NO FREE SPACE ON THE SEGMENT FILES" text is a WARNING template, not an error. Before the reentrant dump, the Backup System installer prints what that message WOULD mean if it appeared. In the session it never fired: DUMP-PROGRAM-REENTRANT completed silently, and LIST-REENTRANT + a working @BACKUP-SYSTEM (Ba-sy: prompt) prove the dump succeeded. Do not mistake the explanatory text for a failure. Note also that the DMA-Server MODE job writes its output to (SYSTEM)BACKUP-LOAD-I:OUT - any error INSIDE that job is invisible on the terminal, so inspect that file when in doubt. Segment files are an ND-100 reentrant-subsystem mechanism; the NLL install itself never uses them (it copies plain files and defines a standard domain), so segment-file space can never explain a missing LINKAGE-LOADER.

G11 - Termination handling is left reset. The Backup System installer resets termination handling to blanks and only prints instructions for restoring it - if the machine had custom @DEFINE-TERMINATION-HANDLING settings, they are gone until redone.

6. Emulator-Specific Notes (RetroCore Session)¶

Floppy images were attached from the debugger: Ctrl-E (stops the CPU, status shows CRASHED - that is the Ctrl-E stop reason, not a real crash), then attach fd0 "...\ND-disk-00042.img" (NLL floppy) / attach fd1 "...\ND-disk-00081.img" (Backup System floppy), then cont.
The two floppies map to FLOPPY-DISC-1 unit 0 and unit 1 for @ENTER-DIRECTORY.
The Backup System install ran a MODE job and multiple reentrant dumps; total wall time for the whole session was on the order of minutes (353601 ms execution time shown at one Ctrl-E stop).

Document created: 2026-07-19 Source: live installation session log (RetroCore ND-100, SINTRAN with ND-500/5000 MONITOR J04), 2026-07-19.