SINTRAN III Line Printer Configuration Inspection Guide¶
Overview¶
This document provides a complete diagnostic guide for SINTRAN III line printer configuration issues, specifically the "NO SUCH LOGICAL UNIT" (error 33) failure when using @COPY-FILE LINE-PRINTER, source-file. It covers the root cause analysis, boot pipeline, symbol cross-references for multiple SINTRAN versions, and step-by-step fix instructions.
Applies to: SINTRAN III versions K03, L07, M06 Target audience: ND-100 emulator developers and SINTRAN system administrators Created: 2026-03-05
Table of Contents¶
- Root Cause Analysis
- Boot Pipeline: From LPSELECTION to Print Output
- Printer Types in SINTRAN
- Symbol Cross-Reference Table
- LPTA Entry Structure
- Memory Inspection Checklist
- Fix: Patching LPSELECTION
- Verification After Patching
- Fallback: Debugging Hardware Detection
- EXR ST vs IOXT Analysis
- Data Flow: Working Print Path
- Key Source Files
Root Cause Analysis¶
Symptom¶
@COPY-FILE LINE-PRINTER, source-file returns error 33: "NO SUCH LOGICAL UNIT"
Error Mechanism¶
The error originates in RP-P2-MONCALLS.NPL:
112256: A:=D; CALL LOGPH % GET ADDR OF DATAFIELDS
...
107240: IF A=0 GO ERR % NO SUCH LOGICAL UNIT
Note: The body of LOGPH is not in any of the 45 available NPL source files. However, a boot-time simulation (CLOGPH/XLOGPH) in PH-P2-OPPSTART.NPL:182 reveals the exact algorithm:
ILOGPH: AD SHZ -6; % Extract group from LDN (shift right 6)
IF A=1 OR A=RDLNO OR A>LGDGMAX THEN
CALL ERRFATAL
FI
A=:X:=D SHZ -12
A+A+CCNVRT(X)+1=:D; *1BANK % CCNVRT[group] = table base, slot = index*2+base+1
IF A-ENTAB(X)>=0 THEN CALL ERRFATAL FI % Bounds check
*2BANK
X:=D; *POF; LDD ,X; PON % Read double word: A=input DF, D=output DF
IF K THEN
IF A><0 THEN X:=A ELSE X:=D FI % Return non-zero DF
...
IF X=0 THEN CALL ERRFATAL FI % Error if both are 0
For logical device 5 (LPLOGNO=5): group=0 (5 >> 6 = 0), index=5. LOGPH looks up CNVRT[0] to find the device group table base, then reads the double word at slot 5. If both words are 0 (LDNT not populated), LOGPH returns 0, and RP-P2-MONCALLS triggers error 33.
Root Cause¶
LPSELECTION = 0 at the LPTA table base address (036370₈ for L07).
The LPTA table is static compiled data in PH-P2-CONFG-TAB.NPL. The first word of each entry (LPSELECTION) is controlled by the SINGEN macro "8LP1:
DATA( 0, 5, 1167, IDMP1, DILP1, DLPR, DMPR1, DMLP1, DLPR, 140230, 3, 3, 0,0,0,0) % LINE PRINTER 1.
The 0 at position 0 is LPSELECTION. Note that all datafield pointers (IDMP1, DILP1, DLPR, DMPR1, DMLP1) and ident codes (140230, 3, 3) are already filled in regardless of LPSELECTION. Only LPSELECTION itself is 0 because SINGEN did not configure a printer type.
When LPSELECTION=0, the boot code CHLPS (line 457: IF A=0 OR A>>3 THEN) immediately sets LPCLENTRY=1 and skips the printer. Then XCHLPS (line 2124: IF X.LPCLENTRY><0 THEN) sees LPCLENTRY != 0 and calls CLLPENTRY which clears the LDNT entry for device 5. Result: LOGPH(5) returns 0.
flowchart TD
SINGEN["SINGEN: No printer configured"]
LPSEL["LPSELECTION = 0 on disk"]
CHLPS["CHLPS: Checks LPSELECTION"]
SKIP["LPSELECTION=0 -> LPCLENTRY=1"]
XCHLPS["XCHLPS: Sees LPCLENTRY != 0"]
CLEAR["CLLPENTRY: Clears LDNT for device 5"]
COPY["COPY FILE LINE PRINTER"]
LOGPH["LOGPH: LDNT entry = 0"]
ERR["Error 33: NO SUCH LOGICAL UNIT"]
SINGEN --> LPSEL --> CHLPS --> SKIP --> XCHLPS --> CLEAR
COPY --> LOGPH --> ERR
classDef error fill:#F44336,stroke:#C62828,stroke-width:2px,color:#fff
classDef warn fill:#FFA726,stroke:#F57C00,stroke-width:2px,color:#000
classDef hw fill:#2196F3,stroke:#1565C0,stroke-width:2px,color:#fff
classDef data fill:#009688,stroke:#00695C,stroke-width:2px,color:#fff
class SINGEN,LPSEL warn
class CHLPS,XCHLPS hw
class SKIP,CLEAR,LOGPH error
class ERR error
class COPY dataWhy There Is No Auto-Discovery¶
The CHLPS code (L07 source, PH-P2-OPPSTART.NPL:455-478) shows a strict gate at line 457:
IF A=0 OR A>>3 THEN
1=:X.LPCLENTRY; GO NXLPENTRY % ILLEGAL SELECTION (OR DON'T USE THIS L-P)
FI
CHLPS only proceeds to hardware testing when LPSELECTION is 1, 2, or 3. The hardware test (EXR ST or IOXT) only verifies that a device responds at the expected IOX address -- it does not scan for unknown devices or determine what type of printer is attached. The printer type must be set in the LPTA table by SINGEN at system generation time. If LPSELECTION=0, no hardware test is attempted and no LDNT entry is created.
Boot Pipeline: From LPSELECTION to Print Output¶
Phase 1: CHLPS - Hardware Detection¶
Source: PH-P2-OPPSTART.NPL:454-478 (exact L07 source code)
043427 INTEGER CSVXY
043430 CHLPS: "0LPTA"=:CSVXY; *1BANK
043433 DO WHILE CSVXY.LPSELECTION><-1 % -1: END OF TABLE
043440 IF A=0 OR A>>3 THEN
043444 1=:X.LPCLENTRY; GO NXLPENTRY % ILLEGAL SELECTION (OR DON'T USE THIS L-P)
043447 FI; A-1+"LPIODF"; X+A
043452 IF X.LPIODF=0 OR X.XLPDMDF=0 THEN % DATAFIELD(S) NOT GENERATED
043456 1=:CSVXY.LPCLENTRY; GO NXLPENTRY
043462 FI; *2BANK
043463 T:=A.HDEV+2; A:=200; *TRR IIE; TRA IIC; 1BANK
043472 IF CSVXY.LPSELECTION-2=0 THEN
043476 *EXR ST
043477 ELSE
043500 *IOXT
043501 FI; *TRA IIC
043502 IF A><0 THEN 1=:X.LPCLENTRY FI % INTERFACE NOT PRESENT
043505 NXLPENTRY:
043505 IF CSVXY.LPSELECTION><3 OR X.LPCLENTRY><0 THEN
043514 X.LPLOGNO=:D; X:="IOBUTAB"
043517 DO WHILE X<<"EIOBUTAB"
043522 IF X.S0/\7777=D THEN 0=:X.S0 FI % REMOVE FROM IOBUTAB
043527 X+2
043530 OD
043531 FI; CSVXY+LPTBSIZE=:CSVXY
043534 OD; *2BANK
Line-by-line analysis:
| Line | Code | Effect |
|---|---|---|
| 455 | "0LPTA"=:CSVXY |
Load pointer to LPTA table (036370₈ in L07) |
| 456 | DO WHILE CSVXY.LPSELECTION><-1 |
Loop until terminator word (-1 = 177777₈) |
| 457 | IF A=0 OR A>>3 THEN |
Gate: LPSELECTION must be 1, 2, or 3 |
| 458 | 1=:X.LPCLENTRY; GO NXLPENTRY |
Fail A: mark disabled, skip |
| 459 | A-1+"LPIODF"; X+A |
Compute I/O datafield pointer for this type (1->offset+3, 2->offset+4, 3->offset+5) |
| 460 | IF X.LPIODF=0 OR X.XLPDMDF=0 |
Check both I/O and DMA datafield addresses exist |
| 461 | 1=:CSVXY.LPCLENTRY; GO NXLPENTRY |
Fail B: datafield not generated |
| 463 | T:=A.HDEV+2 |
T = hardware device address + 2 (status register) |
| 463 | A:=200; *TRR IIE; TRA IIC |
Enable IOX error trap: if IOX fails, A becomes non-zero |
| 464-468 | IF CSVXY.LPSELECTION-2=0 THEN *EXR ST ELSE *IOXT |
Type 2: execute T as instruction; Type 1/3: IOX test via T |
| 469 | IF A><0 THEN 1=:X.LPCLENTRY FI |
Fail C: IOX error means hardware not present |
| 471 | IF CSVXY.LPSELECTION><3 OR X.LPCLENTRY><0 |
Clean up IOBUTAB for disabled printers or non-serial types |
| 477 | CSVXY+LPTBSIZE=:CSVXY |
Advance to next LPTA entry (16 words) |
CHLPS Decision Flow:
flowchart TD
START["CHLPS: Load LPTA table"]
LOOP{"LPSELECTION != -1?"}
CHKSEL{"LPSELECTION\n1, 2, or 3?"}
FAILA["FAIL A:\nLPCLENTRY = 1"]
CHKDF{"Datafield ptrs\nnon zero?"}
FAILB["FAIL B:\nLPCLENTRY = 1"]
LOADHDEV["T = HDEV + 2\nEnable IIE"]
CHKTYPE{"LPSELECTION\n= 2?"}
EXRST["EXR ST\nType 2 Parallel"]
IOXT["IOXT\nType 1 or 3"]
CHKHW{"Hardware\nfound?"}
FAILC["FAIL C:\nLPCLENTRY = 1"]
OK["LPCLENTRY = 0\nPrinter active"]
NEXT["Next LPTA entry"]
DONE["End CHLPS"]
START --> LOOP
LOOP -->|"Yes"| CHKSEL
LOOP -->|"No, terminator"| DONE
CHKSEL -->|"Valid 1 2 3"| CHKDF
CHKSEL -->|"0 or >3"| FAILA
CHKDF -->|"Non zero"| LOADHDEV
CHKDF -->|"Zero"| FAILB
LOADHDEV --> CHKTYPE
CHKTYPE -->|"Yes, Type 2"| EXRST
CHKTYPE -->|"No, Type 1 or 3"| IOXT
EXRST --> CHKHW
IOXT --> CHKHW
CHKHW -->|"Present"| OK
CHKHW -->|"IOX error"| FAILC
FAILA --> NEXT
FAILB --> NEXT
FAILC --> NEXT
OK --> NEXT
NEXT --> LOOP
classDef error fill:#F44336,stroke:#C62828,stroke-width:2px,color:#fff
classDef success fill:#4CAF50,stroke:#2E7D32,stroke-width:2px,color:#fff
classDef hw fill:#2196F3,stroke:#1565C0,stroke-width:2px,color:#fff
classDef decision fill:#FFA726,stroke:#F57C00,stroke-width:2px,color:#000
classDef process fill:#009688,stroke:#00695C,stroke-width:2px,color:#fff
class FAILA,FAILB,FAILC error
class OK success
class EXRST,IOXT,LOADHDEV hw
class CHKSEL,CHKDF,CHKTYPE,CHKHW,LOOP decision
class START,NEXT,DONE processFail Points Summary:
| Fail Point | Condition | Result |
|---|---|---|
| A | LPSELECTION=0 or >3 | LPCLENTRY=1, printer skipped |
| B | Datafield address is 0 | LPCLENTRY=1, printer skipped |
| C | Hardware test fails (IOX error) | LPCLENTRY=1, printer skipped |
Phase 2: XCHLPS - LDNT Population¶
Source: PH-P2-OPPSTART.NPL:2120-2156 (exact L07 source code)
053515 INTEGER CSXXY,CLPSELECTION
053517 XCHLPS:
053517 "0LPTA"=:CSXXY; *1BANK
053522 DO WHILE CSXXY.LPSELECTION><-1
053527 IF X.LPCLENTRY><0 THEN
053531 CALL CLLPENTRY; GO NXTLP % CLEAR ALL TABLE-ENTRIES FOR THIS L-P
053533 FI
053533 IF CSXXY.LPSELECTION=3 THEN
053540 A:=0 % NO DMA-DF
053541 ELSE
053542 A-1+"LPDMDF"; X+A; X.S0 % DMA-DF
053546 FI
053546 A=:D:=CSXXY.LPSELECTION
053551 A-1+"LPIODF"; X+A; X.S0
053555 X:=CSXXY
053556 CALL FAR UPDLPLOGNO % UPDATE LOG.DEV.NO TABLE
053557 IF CSXXY.LPSELECTION=1 THEN % "DMPR-TYPE" PRINTER
053564 X.2LPIDENT; *2BANK
053566 CALL FAR 10IDCLEAR % CLEAR ENTRY IN LEVEL 10 IDENT-CODE-TABLE
053567 ELSE
053570 T:=X.2LPIDENT; A-1+"LPDMDF"; X+A; X.S0=:D
053576 "ITB10"-"PITEX"=:X; *2BANK
053602 A:=MPIFPHPAGE SH 12; X+A+T-1 % X=ADDR IN IDENT-CODE-TABLE (ITB10)
053607 T:=MPIBANK; A:=D; *STATX; 1BANK % UPDATE IDENT-CODE TABLE
053613 CSXXY.1LPDMDF; *2BANK
053616 CALL FAR 11EIDCLEAR % CLEAR "DMPR-TYPE" FROM EXTENDED-IDENT-CODE-TABLE
053617 FI; *1BANK
053620 1=:CLPSELECTION
053622 DO WHILE CLPSELECTION<<=3
053626 IF CLPSELECTION><CSXXY.LPSELECTION THEN
053633 A-1+"LPDMDF"; X+A; X.S0; *2BANK % A=DMA-DF
053640 CALL FAR RFTMTABLE; *1BANK % REMOVE FROM TIMER TABLE
053642 FI; MIN CLPSELECTION
053643 OD
053644 NXTLP: CSXXY+LPTBSIZE=:CSXXY
053647 OD; *2BANK
Line-by-line analysis:
| Line | Code | Effect |
|---|---|---|
| 2123-2125 | IF X.LPCLENTRY><0 THEN CALL CLLPENTRY |
If CHLPS disabled this printer, clear ALL table entries (LDNT, ITB10, ITB11, timer) |
| 2127-2131 | IF CSXXY.LPSELECTION=3 THEN A:=0 ELSE ... X.S0 |
Get DMA datafield (Type 3 has none, so A:=0) |
| 2132-2135 | A=:D:=... CALL FAR UPDLPLOGNO |
Get I/O datafield, call UPDLPLOGNO to write into LDNT |
| 2136-2146 | IF CSXXY.LPSELECTION=1 THEN...ELSE... |
Type 1: clear ITB10 entry; Type 2/3: write DMA-DF into ITB10 at ident code position |
| 2147-2153 | DO WHILE CLPSELECTION<<=3 |
Loop types 1-3, remove timer table entries for unused types |
flowchart TD
START["XCHLPS: For each LPTA entry"]
CHKCL{"LPCLENTRY\n= 0?"}
CLENTRY["CLLPENTRY: line 2092\nClear LDNT, ITB10, ITB11\nClear timer table entries"]
SKIP["GO NXTLP\nSkip to next printer"]
GETDF["Get I/O DF and DMA DF\nfrom LPSELECTION offsets"]
UPDLOG["UPDLPLOGNO: line 2047\nCNVRT lookup\nWrite DF into LDNT via STATX"]
SETITB["Write DMA DF into\nITB10 at ident code position\nline 2140"]
CLEANUP["Loop types 1 to 3\nRFTMTABLE for unused types\nline 2148"]
NEXT["Next LPTA entry\n+16 words"]
START --> CHKCL
CHKCL -->|"Yes, LPCLENTRY=0"| GETDF
CHKCL -->|"No, LPCLENTRY!=0"| CLENTRY
CLENTRY --> SKIP --> NEXT
GETDF --> UPDLOG --> SETITB --> CLEANUP --> NEXT
classDef error fill:#F44336,stroke:#C62828,stroke-width:2px,color:#fff
classDef success fill:#4CAF50,stroke:#2E7D32,stroke-width:2px,color:#fff
classDef decision fill:#FFA726,stroke:#F57C00,stroke-width:2px,color:#000
classDef process fill:#009688,stroke:#00695C,stroke-width:2px,color:#fff
class CLENTRY,SKIP error
class UPDLOG,SETITB success
class CHKCL decision
class START,GETDF,CLEANUP,NEXT processHow UPDLPLOGNO writes the LDNT (PH-P2-OPPSTART.NPL:2047-2062):
UPDLPLOGNO:
AD=:CSVAD; X=:CXXX1 % Save A=I/O-DF, D=DMA-DF
IF X.LPLOGNO><0 THEN % LPLOGNO=5 for LP1
A=:D SHZ -6; *2BANK % Extract group (5>>6 = 0)
X:=CNVRT(A); A:=D/\77 SH 1+1; X+A % CNVRT[0] + index*2 + 1 = slot address
T:=LOGDBANK; A:=CSVAA; *STATX 10; STZTX % Write: LOG.NO-OUT=I/O-DF, LOG.NO-IN=0
*1BANK
FI
IF CXXX1.LPDMLOGNO><0 THEN % LPDMLOGNO=1167 for LP1
... % Similarly write DMA-DF into LDNT
FI; EXIT
This writes the I/O datafield address (e.g., DILP1=107102₈ for Type 2) into the LDNT slot for logical device 5. After this, LOGPH(5) will find the datafield and return it instead of 0.
Phase 3: COPY-FILE Data Flow (when working)¶
flowchart TD
CMD["@COPY FILE LINE PRINTER, source"]
OPEN["Open peripheral file\nResolves to logical device 5"]
OUTBT["OUTBT MON 2\nwith device 5"]
LOGPH["LOGPH: LDNT lookup\nReturns datafield address"]
BIOTR["BIOTR: Output buffer handler"]
LPPUT["IOTRANS -> LPPUT\n7 bit ASCII translation"]
STDEV["STDEV: Start device driver"]
TLPRINT["TLPRINT: Level 11 transfer"]
subgraph HWLOOP [Hardware IO Loop]
WRCHAR["IOX 0431: Write character"]
WRCTRL["IOX 0433: Write control word\nActivate + IE"]
WAIT["Wait for Level 10\nreadyForTransfer interrupt"]
IDENT["IDENT PL10\nIdent code 3 -> ITB10"]
end
CMD --> OPEN --> OUTBT --> LOGPH --> BIOTR --> LPPUT --> STDEV --> TLPRINT
TLPRINT --> WRCHAR --> WRCTRL --> WAIT --> IDENT
IDENT -->|"Next character"| WRCHAR
classDef cmd fill:#009688,stroke:#00695C,stroke-width:2px,color:#fff
classDef kernel fill:#3F51B5,stroke:#283593,stroke-width:2px,color:#fff
classDef driver fill:#2196F3,stroke:#1565C0,stroke-width:2px,color:#fff
classDef hw fill:#E91E63,stroke:#AD1457,stroke-width:2px,color:#fff
class CMD,OPEN cmd
class OUTBT,LOGPH,BIOTR,LPPUT kernel
class STDEV,TLPRINT driver
class WRCHAR,WRCTRL,WAIT,IDENT hwPrinter Types in SINTRAN¶
| LPSELECTION | Config Name | NPL Driver | Boot HW Test | Ident (LP1) | Ident (LP2) |
|---|---|---|---|---|---|
| 0 | Not configured | -- | Skipped | -- | -- |
| 1 | DMA (Fujitsu) | DMPR | *IOXT |
140230₈ | 140231₈ |
| 2 | Parallel (CDC/DP) | DMLP | *EXR ST |
3₈ | 23₈ |
| 3 | Serial | DLPR | *IOXT |
3₈ | 23₈ |
Other print-capable devices in SINTRAN:
- Terminal-based matrix printers (ND device 414-417, name "PRINTER")
- Versatec printers/plotters (ND device 603-606, name "LINE-PRINTER-1")
- Any device reachable via spooling (@APPEND-SPOOLING)
Emulator CDC 9380 implementation: Parallel = Type 2 (DMLP), ident code 3₈
Symbol Cross-Reference Table¶
Core Addresses (version-dependent)¶
| Symbol | K03 | L07 | M06 | Description |
|---|---|---|---|---|
| 0LPTA | 033172₈ | 036370₈ | 036241₈ | Line printer config table |
| 0SPTA | 033233₈ | 036431₈ | 036302₈ | Spooling device table |
| CNVRT | 004327₈ | 004327₈ | 004327₈ | LDNT group conversion table |
| LOGDB | 006545₈ | 006620₈ | 006604₈ | Logical device bank |
| ITB10 | 126156₈ | 153414₈ | 155732₈ | Ident table level 10 |
| ITB11 | 126325₈ | 077637₈ | 077425₈ | Ident table level 11 |
| ITB12 | 126347₈ | 153563₈ | 156101₈ | Ident table level 12 |
Printer Datafield Addresses (version-dependent)¶
| Symbol | K03 | L07 | M06 | Description |
|---|---|---|---|---|
| DMLP1 | 052321₈ | 107006₈ | 106012₈ | LP1 Type 2 (Parallel) datafield |
| DILP1 | 052415₈ | 107102₈ | 106106₈ | LP1 Type 2 input datafield |
| DMPR1 | 052532₈ | 107217₈ | 106223₈ | LP1 Type 1 (DMA) datafield |
| IDMP1 | 052563₈ | 107250₈ | 106255₈ | LP1 Type 1 main datafield |
| DLPR | 053203₈ | 107670₈ | 106676₈ | LP1 Type 3 (Serial) datafield |
| DMLP2 | 052667₈ | 107354₈ | 106361₈ | LP2 Type 2 datafield |
| DMPR2 | 053100₈ | 107565₈ | 106572₈ | LP2 Type 1 datafield |
| IDMP2 | 053131₈ | 107616₈ | 106624₈ | LP2 Type 1 main datafield |
| DLPR2 | 053236₈ | 107723₈ | 106731₈ | LP2 Type 3 datafield |
Fixed Offsets (same across all versions)¶
| Symbol | Value | Description |
|---|---|---|
| LPTBS | 000020₈ (16 words) | LPTA entry size |
| 0NLPS | 000002₈ | Number of line printers |
| HDEV | 177775₈ (-3) | HW device address offset in datafield |
| XHDEV | 177774₈ (-4) | Extended HW device offset |
| STDEV | 000010₈ | Start device routine offset |
| LPSEL | 000000₈ | LPSELECTION offset in LPTA entry |
LPTA Entry Structure¶
Each LPTA entry is 16 words (020₈). The table starts at 0LPTA and contains 0NLPS (2) entries, terminated by -1 (177777₈).
block-beta
columns 4
block:header:4
columns 4
H0["Word +0\nLPSELECTION\n0=off 1=DMA\n2=Par 3=Ser"]
H1["Word +1\nLPLOGNO\nLogical dev num"]
H2["Word +2\nLPDMLOGNO\nDMA logical num"]
H3["Word +3\n1LPIODF\nType 1 IO df"]
end
block:datafields:4
columns 4
D0["Word +4\n2LPIODF\nType 2 IO df"]
D1["Word +5\n3LPIODF\nType 3 IO df"]
D2["Word +6\n1LPDMDF\nType 1 DMA df"]
D3["Word +7\n2LPDMDF\nType 2 DMA df"]
end
block:identcodes:4
columns 4
I0["Word +10\n3LPDMDF\nType 3 DMA df"]
I1["Word +11\n1LPIDENT\nType 1 ident"]
I2["Word +12\n2LPIDENT\nType 2 ident"]
I3["Word +13\n3LPIDENT\nType 3 ident"]
end
block:footer:4
columns 4
F0["Word +14\nLPCLENTRY\n0=OK, !=0 off"]
F1["Word +15\nreserved"]
F2["Word +16\nreserved"]
F3["Word +17\nreserved"]
end
style H0 fill:#F44336,stroke:#C62828,stroke-width:2px,color:#fff
style D0 fill:#2196F3,stroke:#1565C0,stroke-width:2px,color:#fff
style D3 fill:#2196F3,stroke:#1565C0,stroke-width:2px,color:#fff
style I2 fill:#009688,stroke:#00695C,stroke-width:2px,color:#fff
style F0 fill:#FFA726,stroke:#F57C00,stroke-width:2px,color:#000Legend: LPSELECTION (red) is the root cause field. Datafield pointers (blue) must be non-zero for the selected type. Ident code (teal) maps to ITB10 interrupt dispatch. LPCLENTRY (amber) indicates boot detection result.
| Offset | Symbol | Description |
|---|---|---|
| +0 | LPSELECTION | Printer type: 0=off, 1=DMA, 2=Parallel, 3=Serial |
| +1 | LPLOGNO | Main logical device number |
| +2 | LPDMLOGNO | DMA datafield logical number |
| +3 | 1LPIODF | Type 1 (DMPR) I/O datafield address |
| +4 | 2LPIODF | Type 2 (DMLP) I/O datafield address |
| +5 | 3LPIODF | Type 3 (DLPR) I/O datafield address |
| +6 | 1LPDMDF | Type 1 DMA datafield address |
| +7 | 2LPDMDF | Type 2 DMA datafield address |
| +10₈ | 3LPDMDF | Type 3 DMA datafield address |
| +11₈ | 1LPIDENT | Type 1 ident code |
| +12₈ | 2LPIDENT | Type 2 ident code |
| +13₈ | 3LPIDENT | Type 3 ident code |
| +14₈ | LPCLENTRY | Clear flag: 0=OK, non-zero=disabled by boot |
| +15₈-17₈ | (reserved) | Padding to 16-word boundary |
Source: PH-P2-CONFG-TAB.NPL -- actual DATA statement:
INTEGER ARRAY 0LPTA(0)
*"8LP1+8DLP1+8NLP1+8DVE1
"DATA( 0, 5, 1167, IDMP1, DILP1, DLPR, DMPR1, DMLP1, DLPR, 140230, 3, 3, 0,0,0,0) % LINE PRINTER 1.
*"8LP2+8DLP2+8NLP2+8DVE2
"DATA( 0, 15, 1175, IDMP2, DILP2, DLPR2, DMPR2, DMLP2, DLPR2, 140231, 23, 23, 0,0,0,0) % LINE PRINTER 2.
DATA( -1) % END OF TABLE TERMINATOR
The "8LP1 SINGEN macro controls the LPSELECTION value (word 0). All other fields (datafield addresses, ident codes) are filled in at compile time regardless of LPSELECTION.
Memory Inspection Checklist¶
Use these addresses for SINTRAN L07. For other versions, substitute from the Symbol Cross-Reference Table.
Diagnostic Decision Tree¶
flowchart TD
START["Error 33: NO SUCH LOGICAL UNIT"]
S1{"Step 1:\nLPSELECTION\nat 036370?"}
FIX1["FIX: Patch LPSELECTION\nfrom 0 to 2"]
S2{"Step 2:\nDatafield ptrs\nnon zero?"}
FIX2["Disk image corruption\nRegenerate with SINGEN"]
S3{"Step 3:\nHDEV = 0430?"}
FIX3["Wrong HDEV value\nCheck datafield integrity"]
S4{"Step 4:\nLPCLENTRY = 0\nafter boot?"}
FIX4["HW test failed\nCheck EXR ST or try Type 3"]
S5{"Step 5:\nLDNT entry\nnon zero?"}
FIX5["XCHLPS did not run\nCheck boot sequence"]
S6["Configuration OK\nCheck file system\nand peripheral file"]
START --> S1
S1 -->|"= 0"| FIX1
S1 -->|"1, 2, or 3"| S2
S2 -->|"Zero"| FIX2
S2 -->|"Non zero"| S3
S3 -->|"Wrong"| FIX3
S3 -->|"= 0430"| S4
S4 -->|"!= 0"| FIX4
S4 -->|"= 0"| S5
S5 -->|"= 0"| FIX5
S5 -->|"Non zero"| S6
classDef error fill:#F44336,stroke:#C62828,stroke-width:2px,color:#fff
classDef success fill:#4CAF50,stroke:#2E7D32,stroke-width:2px,color:#fff
classDef decision fill:#FFA726,stroke:#F57C00,stroke-width:2px,color:#000
classDef start fill:#009688,stroke:#00695C,stroke-width:2px,color:#fff
class FIX1,FIX2,FIX3,FIX4,FIX5 error
class S6 success
class S1,S2,S3,S4,S5 decision
class START startStep 1: Check LPSELECTION¶
Address: 036370₈ (word 0 of LPTA LP1 entry)
Dump 16 words at 036370:
Word +0: LPSELECTION -- must be 1, 2, or 3 (NOT 0)
Word +1: LPLOGNO -- should be 5 (logical device number)
Word +14: LPCLENTRY -- should be 0 after successful boot
If LPSELECTION = 0: This is the root cause. The printer was not configured in SINGEN. Proceed to Fix: Patching LPSELECTION.
Step 2: Check Datafield Pointers¶
Based on the LPSELECTION value, verify the datafield addresses are populated:
| LPSELECTION | I/O Datafield (offset) | Expected Value (L07) | DMA Datafield (offset) | Expected Value (L07) |
|---|---|---|---|---|
| 1 | +3 (1LPIODF) | IDMP1 = 107250₈ | +6 (1LPDMDF) | DMPR1 = 107217₈ |
| 2 | +4 (2LPIODF) | DILP1 = 107102₈ | +7 (2LPDMDF) | DMLP1 = 107006₈ |
| 3 | +5 (3LPIODF) | DLPR = 107670₈ | +10 (3LPDMDF) | (may be 0) |
If either datafield address is 0: Boot code sets LPCLENTRY=1 at Fail Point B.
Step 3: Check HDEV in the Datafield¶
Read HDEV at offset -3 from the selected I/O datafield reference:
| LPSELECTION | Datafield | HDEV address (L07) | Expected HDEV value |
|---|---|---|---|
| 1 | IDMP1 = 107250₈ | 107250 - 3 = 107245₈ | 0430₈ |
| 2 | DILP1 = 107102₈ | 107102 - 3 = 107077₈ | 0430₈ |
| 3 | DLPR = 107670₈ | 107670 - 3 = 107665₈ | 0430₈ |
HDEV should be 0430₈ (LP1 IOX base address). The boot code computes the test address as HDEV+2 = 0432₈ (status register).
Step 4: Check LPCLENTRY After Boot¶
Address: 036370₈ + 014₈ = 036404₈
Read word at 036404:
If 0: Boot hardware test passed, printer active
If non-0: Boot disabled the printer (hardware test failed)
Step 5: Check LDNT Entry for Device 5¶
1. Read CNVRT at 004327 -- get first word (CNVRT[0])
2. CNVRT[0] is a page number in LOGDBANK
3. Entry for device 5: offset = 5 * 2 + 1 = 013
4. If entry is 0 -> LDNT not populated -> confirms root cause
Step 6: Check Ident Code¶
Address (L07): Word +12₈ in LPTA = 036370₈ + 012₈ = 036402₈
For Type 2 (Parallel), ident code should be 3₈. This value is used to set up the ITB10 interrupt dispatch table entry during XCHLPS.
Fix: Patching LPSELECTION¶
What to Patch¶
| Version | Address | Current Value | New Value | Meaning |
|---|---|---|---|---|
| K03 | 033172₈ | 000000 | 000002 | Enable Parallel/CDC printer |
| L07 | 036370₈ | 000000 | 000002 | Enable Parallel/CDC printer |
| M06 | 036241₈ | 000000 | 000002 | Enable Parallel/CDC printer |
Value 2 = Parallel/CDC printer type (DMLP), which matches the emulator's CDC 9380 implementation.
Method: Patch the Disk Image¶
The LPTA table resides in the SINTRAN system area on disk. Patch word 0 of the table from 000000 to 000002 in the disk image file before booting.
Method: Patch Memory After Load¶
Alternatively, patch the word in memory after the SINTRAN image is loaded but before boot code runs CHLPS. This avoids modifying the disk image.
What Happens After Patching¶
With LPSELECTION=2, the CHLPS boot code will:
- See LPSELECTION=2 (valid, passes Fail Point A check)
- Load Type 2 datafield addresses from +4 (2LPIODF) and +7 (2LPDMDF)
- Verify datafields are non-zero (passes Fail Point B check)
- Read HDEV from the datafield, compute T = HDEV+2 = 0432₈
- Use
*EXR ST(Type 2 path) to test printer presence - If no IOX error: LPCLENTRY stays 0 (passes Fail Point C)
- XCHLPS sees LPCLENTRY=0, calls UPDLPLOGNO to populate LDNT entry for device 5
@COPY-FILE LINE-PRINTER, filefinds device 5 in LDNT and proceeds
flowchart LR
PATCH["Patch\nLPSELECTION=2"]
BOOT["Reboot\nSINTRAN"]
CHLPS["CHLPS:\nValid type\nPass A"]
DF["Datafields\nnon zero\nPass B"]
EXR["EXR ST\nIOX 0432\nPrinter found\nPass C"]
XCHLPS["XCHLPS:\nUPDLPLOGNO\nPopulate LDNT"]
WORK["COPY FILE\nLINE PRINTER\nworks"]
PATCH --> BOOT --> CHLPS --> DF --> EXR --> XCHLPS --> WORK
classDef fix fill:#FFA726,stroke:#F57C00,stroke-width:2px,color:#000
classDef pass fill:#4CAF50,stroke:#2E7D32,stroke-width:2px,color:#fff
classDef hw fill:#2196F3,stroke:#1565C0,stroke-width:2px,color:#fff
class PATCH,BOOT fix
class CHLPS,DF,EXR pass
class XCHLPS hw
class WORK passVerification After Patching¶
After rebooting with LPSELECTION=2:
Check 1: LPCLENTRY¶
Read word at 036404₈ (L07). Must be 0 (hardware test passed).
Check 2: LDNT Entry¶
Follow the LDNT lookup from Step 5. The entry for device 5 should now contain a non-zero datafield address.
Check 3: Functional Test¶
@COPY-FILE LINE-PRINTER, test-file
Should produce output on the emulated printer without error 33.
Fallback: Debugging Hardware Detection¶
If LPCLENTRY becomes 1 after reboot (hardware test failed), the EXR ST instruction did not successfully reach the printer.
Add Emulator Logging¶
In devicemanager.c -- log printer IOX accesses:
if (address >= 0430 && address <= 0433) {
printf("LP IOX %s addr=%06o val=%06o\n",
is_write ? "WR" : "RD", address, value);
}
In cpu_instr.c around DoEXR -- log EXR executions:
printf("EXR: T=%06o executing=%06o\n", gT, exr_instr);
Try LPSELECTION=3 (Serial) Instead¶
If Type 2 (Parallel/CDC) fails because *EXR ST does not properly trigger an IOX, try LPSELECTION=3 (Serial). Type 3 uses *IOXT for hardware testing, which directly issues an IOX to the T register address. The ident codes are the same (3₈), so the rest of the pipeline should work identically.
Patch the same address with value 000003 instead of 000002.
EXR ST vs IOXT Analysis¶
The boot hardware test uses different instructions depending on printer type:
- Type 2 (Parallel/CDC):
*EXR ST-- execute instruction from T register - Type 1/3 (DMA/Serial):
*IOXT-- IOX Test using T register as address
How EXR Works¶
void DoEXR(ushort instr) {
sr = (instr >> 3) & 0x07; // sr=6 for T register
exr_instr = gReg->reg[CurrLEVEL][sr]; // Read T register value
do_op(exr_instr, true); // Execute as instruction
}
The value in T is executed as a machine instruction. If T contains an IOX-like value, it may or may not trigger an actual IOX depending on encoding.
Instruction Path Comparison¶
flowchart TD
subgraph TYPE2 [Type 2: Parallel CDC]
T2HDEV["HDEV + 2 -> T register"]
T2EXR["EXR ST:\nExecute T as instruction"]
T2DO["do_op: Decode T value"]
T2IOX["If IOX encoded:\nndfunc_iox masks to 11 bits"]
T2IO["io_op: Access IOX 0432"]
end
subgraph TYPE13 [Type 1 and 3: DMA Serial]
T13HDEV["HDEV + 2 -> T register"]
T13IOXT["IOXT:\nIOX Test using T as address"]
T13IO["io_op: Access full T value"]
end
subgraph RESULT [Detection Result]
FOUND["Printer found\nLPCLENTRY = 0"]
NOTFOUND["IOX error\nLPCLENTRY = 1"]
end
T2HDEV --> T2EXR --> T2DO --> T2IOX --> T2IO
T13HDEV --> T13IOXT --> T13IO
T2IO --> FOUND
T13IO --> FOUND
T2IO --> NOTFOUND
T13IO --> NOTFOUND
classDef hw fill:#2196F3,stroke:#1565C0,stroke-width:2px,color:#fff
classDef code fill:#E91E63,stroke:#AD1457,stroke-width:2px,color:#fff
classDef success fill:#4CAF50,stroke:#2E7D32,stroke-width:2px,color:#fff
classDef error fill:#F44336,stroke:#C62828,stroke-width:2px,color:#fff
class T2HDEV,T13HDEV hw
class T2EXR,T2DO,T2IOX,T13IOXT code
class T2IO,T13IO hw
class FOUND success
class NOTFOUND errorWhat HDEV Contains¶
Scenario A: HDEV = plain IOX address (e.g., 0430₈)
- T = 0430 + 2 = 0432₈
- IOXT path: io_op(0432) -> printer found
- EXR ST path: executes 0432₈ as MRI -> no IOX error -> device "present" (but doesn't actually test HW)
Scenario B: HDEV = IOX instruction encoding (e.g., 0164430₈)
- T = 0164430 + 2 = 0164432₈
- EXR ST path: do_op(0164432) -> ndfunc_iox() -> masks to 11 bits -> io_op(0432) -> printer found
- IOXT path: io_op(0164432) = io_op(59674) -> NO device -> IOX ERROR
Most likely: HDEV contains a plain IOX address. Both paths should pass boot detection.
Data Flow: Working Print Path¶
When the printer is properly configured and LDNT is populated:
flowchart TD
subgraph USER [User Command Layer]
CMD["@COPY FILE LINE PRINTER, source"]
OPEN["Open peripheral file\nResolves to logical device 5"]
end
subgraph KERNEL [Kernel Monitor Call Layer]
OUTBT["OUTBT MON 2\ndevice 5"]
LOGPH["LOGPH\nLDNT lookup via CNVRT\nReturns datafield addr"]
BIOTR["BIOTR\nOutput buffer handler"]
end
subgraph DRIVER [Device Driver Layer]
LPPUT["IOTRANS -> LPPUT\nCharacter translation\n7 bit ASCII"]
STDEV["STDEV -> TLPRINT\nLevel 11 transfer"]
end
subgraph HARDWARE [Hardware IO Layer]
WRCHAR["IOX 0431\nWrite character"]
WRCTRL["IOX 0433\nWrite control + IE"]
WAIT["Level 10 interrupt\nreadyForTransfer"]
IDENT["IDENT PL10\nCode 3 -> ITB10\n-> datafield"]
end
CMD --> OPEN --> OUTBT --> LOGPH --> BIOTR --> LPPUT --> STDEV
STDEV --> WRCHAR --> WRCTRL --> WAIT --> IDENT
IDENT -->|"Next char"| WRCHAR
classDef user fill:#009688,stroke:#00695C,stroke-width:2px,color:#fff
classDef kernel fill:#3F51B5,stroke:#283593,stroke-width:2px,color:#fff
classDef driver fill:#2196F3,stroke:#1565C0,stroke-width:2px,color:#fff
classDef hw fill:#E91E63,stroke:#AD1457,stroke-width:2px,color:#fff
class CMD,OPEN user
class OUTBT,LOGPH,BIOTR kernel
class LPPUT,STDEV driver
class WRCHAR,WRCTRL,WAIT,IDENT hwLayer Legend: - Teal = User command layer - Indigo = Kernel monitor call layer (LOGPH, BIOTR) - Blue = Device driver layer (LPPUT, TLPRINT) - Magenta = Hardware I/O layer (IOX registers, interrupts)
Key Source Files¶
| File | Content | Status |
|---|---|---|
PH-P2-CONFG-TAB.NPL |
LPTA table DATA statement, SINGEN macros | Verified |
PH-P2-OPPSTART.NPL:454-478 |
CHLPS boot detection (exact source above) | Verified |
PH-P2-OPPSTART.NPL:182-209 |
CLOGPH/XLOGPH - LOGPH simulation revealing algorithm | Verified |
PH-P2-OPPSTART.NPL:2039-2062 |
UPDLPLOGNO - writes DF into LDNT | Verified |
PH-P2-OPPSTART.NPL:2082-2116 |
CLLPENTRY - clears LDNT, ITB10, ITB11, timer | Verified |
PH-P2-OPPSTART.NPL:2118-2156 |
XCHLPS - LDNT population (exact source above) | Verified |
PH-P2-START-BASE.NPL:207-210 |
CCNVRT array (compile-time CNVRT copy) | Verified |
CC-P2-COMMON.NPL:50-105 |
CFLOGDV/9GTLOGDV - reverse LOGPH using CNVRT | Verified |
RP-P2-MONCALLS.NPL:112256 |
A:=D; CALL LOGPH - device 5 lookup |
Verified |
RP-P2-MONCALLS.NPL:107240 |
IF A=0 GO ERR - error 33 trigger |
Verified |
RP-P2-MONCALLS.NPL:3433 |
BIOTR output handler | Call site verified |
MP-P2-2.NPL:070540 |
LPPUT character translation | Call site verified |
IP-P2-1.NPL:044060 |
TLPRINT driver | Call site verified |
| LOGPH (body) | Actual LOGPH procedure | Not in available source |
Note: The body of LOGPH is not in any of the 45 available NPL source files. It is called via CALL LOGPH from 14+ files. The algorithm is known from the boot-time simulation CLOGPH/XLOGPH at PH-P2-OPPSTART.NPL:182.
NPL source location: ../NPL-SOURCE/NPL/ Symbol tables: ../NPL-SOURCE/SYMBOLS/
Related Documentation¶
- DEVICE_DRIVER_SETUP_DOCUMENTATION.md -- LPTA decoded, datafield structure
- ../OS/18-DEVICE-DRIVER-FRAMEWORK.md -- Driver framework
- ../OS/13-INT14-HANDLER-DETAILED.md -- Interrupt system
- ../../Operations/SINTRAN/ND-30.003.007 EN SINTRAN III System Supervisor.md -- Printer setup guide
Parent: README.md -- Device Documentation Index Sibling: ../OS/README.md -- Operating System Documentation
Diagnostic guide based on analysis of SINTRAN III NPL source code and ND-100 emulator testing.