NDInsight - NORD Computer Systems Analysis & Documentation

Comprehensive technical analysis and documentation for Norsk Data NORD computer systems

📖 Overview

NDInsight is a centralized repository of deep technical analysis, reverse-engineered documentation, and implementation guides for the Norsk Data NORD computer systems, focusing on the SINTRAN III operating system and its hardware architecture.

The analysis is made from original SINTRAN III source code, Norsk Data technical manuals, and with heavy use of AI (Claude AI, Cursor AI, ChatGPT AI). While comprehensive, there might be errors and hallucinations - use with appropriate verification.

What's Inside

SINTRAN III NPL source code - 45 files of authentic operating system source code
SINTRAN L07 symbol tables - 7 files mapping memory addresses to kernel structures
Kernel-level documentation extracted from SINTRAN III source code
Hardware analysis of communication protocols (HDLC, X.21, TAD)
ND-500 coprocessor integration and communication
Device driver implementation details (with complete source code)
SCSI subsystem analysis (with complete source code)
Emulator implementation guides and C# code
Complete reference manuals for all NORD/SINTRAN components and languages

🗂️ Repository Structure

NDInsight/
├── README.md                    ← You are here
├── MERMAID_COLOR_STANDARDS.md   ← Diagram color standards
├── Developer/                   ← Developer guides and language references
├── Reference-Manuals/           ← Complete NORD/SINTRAN reference manuals
└── SINTRAN/                     ← SINTRAN III Operating System
    ├── Devices/                 ← Hardware device documentation
    ├── Emulator/                ← C# emulator implementation guides
    ├── ND500/                   ← ND-500 coprocessor documentation
    ├── NPL-SOURCE/              ← ⭐ SINTRAN III source code & symbols
    ├── OS/                      ← Core OS kernel documentation
    └── TAD/                     ← TAD protocol analysis

🚀 Quick Start

New to SINTRAN III?

Start with these documents:

SINTRAN/OS/00-SINTRAN-ARCHITECTURE-OVERVIEW.md - System overview
SINTRAN/OS/01-BOOT-SEQUENCE.md - How the system boots
SINTRAN/README.md - Complete SINTRAN documentation guide

Building an Emulator?

Critical resources:

SINTRAN/NPL-SOURCE/README.md - Access to actual source code
SINTRAN/Emulator/README.md - C# implementation guides
SINTRAN/OS/19-MEMORY-MAP-REFERENCE.md - Memory layout

Developing Software?

Language guides:

Developer/README.md - Developer documentation index
Reference-Manuals/README.md - Complete language references

📂 Main Sections

Developer/ - Development Guides

Complete guides for developing software on SINTRAN III systems.

Contents:

Languages/ - NPL, MAC, PLANC, PASCAL, FORTRAN, COBOL, BASIC, C
Editors/ - QED, PED, LED editor guides
Workflow/ - Compiler, linker, tools, scripts

📖 See Developer/README.md for full details

Reference-Manuals/ - Official Documentation

Authoritative reference manuals for all NORD/SINTRAN components (25 complete manuals, ~2.2MB).

Categories:

System & CPU Architecture (ND-500, SINTRAN Commands)
Assemblers (NORD-500 Assembler, MAC, MACM)
System Programming (NPL)
Application Languages (PLANC, PASCAL, FORTRAN, COBOL, BASIC)
Editors (QED, PED)
System Tools (Relocating Loader)

📖 See Reference-Manuals/README.md for full index

SINTRAN/ - Operating System Documentation

Comprehensive documentation for SINTRAN III operating system (140+ files, ~5.6MB).

Key Subdirectories

Directory	Description	Details
NPL-SOURCE/ ⭐	SINTRAN III source code	45 NPL files + 7 symbol tables (4.4MB)
OS/	Core kernel documentation	31 files covering chapters 00-19 (518KB)
Devices/	Hardware device drivers	HDLC (30+ docs) + SCSI (10+ docs)
Emulator/	C# emulator implementation	5 files with production code
ND500/	ND-500 coprocessor	Integration and communication
TAD/	TAD protocol	Terminal access protocol analysis

📖 See SINTRAN/README.md for complete overview

SINTRAN/NPL-SOURCE/ - Source Code ⭐

Authentic SINTRAN III operating system source code from the s3vs-4 build job.

What's Included:

45 NPL source files - Kernel, device drivers, ND-500 interface, disk I/O
7 symbol tables (SINTRAN L07) - Memory addresses and kernel structures
s3vs-4.symb - Original 3.9MB build output

Key Components:

5P-P2-MON60.NPL - Monitor/kernel core
IP-P2-SCSI-*.NPL - SCSI drivers (complete implementation)
MP-P2-HDLC-DRIV.NPL - HDLC communication driver
CC-P2-N500.NPL, MP-P2-N500.NPL - ND-500 interface code

📖 See SINTRAN/NPL-SOURCE/README.md for details

SINTRAN/OS/ - Kernel Documentation

Complete kernel documentation extracted from SINTRAN III source code (31 files, 518KB).

Chapters 00-19:

00: Architecture Overview
01-12: Boot, queues, MMU, ND-500 integration, memory
13: Interrupt handler (Level 14)
14: Monitor kernel and system calls
15: Disk I/O subsystem
16: Page fault handler
17: Scheduler and priorities
18: Device driver framework
19: Memory map reference

📖 See SINTRAN/OS/README.md for complete index

SINTRAN/Devices/ - Hardware Devices

Device driver documentation with complete source code analysis.

HDLC/ - High-Level Data Link Control

COM5025 chip specification
X.21 interface protocol
LAPB/X.25 protocol implementation
C# emulator guide

SCSI/ - SCSI Disk Controllers

NCR 5386 protocol controller
27 SCSI commands documented
Disk, optical, tape drivers
C# implementation guide

📖 See SINTRAN/Devices/README.md for details

SINTRAN/Emulator/ - Emulator Implementation

C# emulator implementation guides with production code.

Contents:

KERNEL-ACCESS-EMULATOR.md - Reading kernel structures from C#
ND500-EMULATION-COMPLETE.cs - Complete ND-500 emulation (677 lines)
ND500-INTEGRATION-GUIDE.md - Step-by-step integration guide
ND500-QUICK-REFERENCE.md - Quick reference card

📖 See SINTRAN/Emulator/README.md for details

📊 Repository Statistics

Documentation by Category

Category	Files	Size	Status
NPL Source Code	45	3.9MB	✅ Complete (s3vs-4)
Symbol Tables (L07)	7	450KB	✅ Complete
Reference Manuals	25	~2.2MB	✅ Complete Collection
OS Kernel Docs	31	518KB	✅ Phase 1 Complete
HDLC Analysis	30+	~350KB	✅ Consolidated
SCSI Analysis	10+	~125KB	✅ Complete
Developer Guides	20+	~500KB	✅ Multiple Languages
Emulator Code	6	~100KB	✅ Production Ready
ND-500 Docs	6+	~200KB	✅ Complete
TAD Protocol	7	~150KB	✅ Complete
Total	187+	~8.2MB	-

Source Code Coverage

What We Have (NPL Source):

✅ Kernel/Monitor core (MON60)
✅ SCSI device drivers (disk, optical, tape)
✅ HDLC communication driver
✅ ND-500 interface code
✅ Disk I/O subsystem
✅ Segment administration
✅ HASP protocol
✅ Terminal handlers (partial)

What's Missing:

❌ File system implementation (but symbols available)
❌ XMSG message system (but symbols available)
❌ Complete terminal handlers
❌ Network subsystems (beyond HDLC)
❌ Batch processing components

Documentation Quality Metrics

Metric	Value
Total Words	~100,000+ words
Code Examples	200+ NPL/C# examples
Mermaid Diagrams	40+ diagrams
Reference Tables	150+ tables
Cross-References	300+ internal links
Production C# Code	~2,700 lines

🛠️ Technologies Documented

Hardware

NORD-10/100 - 16-bit minicomputer (1970s-1980s)
ND-500 - 32-bit coprocessor
MPM5 - Multiport memory (shared RAM)
COM5025 - HDLC controller chip
NCR 5386 - SCSI protocol controller

Software

SINTRAN III - Real-time operating system
NPL - NORD Programming Language (system programming)
MAC - Macro assembler
PLANC, PASCAL, FORTRAN, COBOL, BASIC, C - Application languages

Protocols

HDLC - High-Level Data Link Control
X.21 - Serial interface standard
X.25 - Packet switching protocol
LAPB - Link Access Procedure Balanced
TAD - Terminal Access Device protocol

🎓 Documentation Methodology

Sources

SINTRAN III Source Code - Direct NPL source analysis (s3vs-4 build)
Hardware Manuals - Official Norsk Data documentation
Protocol Specifications - HDLC, X.21, X.25, TAD standards
Reverse Engineering - Bit-level analysis when needed

Quality Standards

✅ No guesswork - Only verified facts from source/manuals
✅ Source citations - Every claim traced to source
✅ Cross-references - Extensive linking between documents
✅ Visual aids - Mermaid diagrams for complex flows
✅ Production code - Working C# implementations included
✅ WCAG 2.1 AA - Accessible diagram color standards

📂 Complete Folder Navigation

Each major folder has its own README for detailed navigation:

Folder	README	Contents
Reference-Manuals/	README.md	15 complete NORD/SINTRAN reference manuals
Developer/	README.md	Development guides, quick-starts, language references
Developer/Languages/	README.md	System & Application language guides
Developer/Workflow/	README.md	Compiler commands, linking, tools
SINTRAN/	README.md	SINTRAN III complete documentation overview
SINTRAN/NPL-SOURCE/	README.md	Source code & symbol tables
SINTRAN/OS/	README.md	Operating system kernel (chapters 00-19)
SINTRAN/Devices/	README.md	Hardware device documentation
SINTRAN/Devices/HDLC/	README.md	HDLC communication controller
SINTRAN/Devices/SCSI/	README.md	SCSI disk controllers
SINTRAN/Emulator/	README.md	C# emulator implementation
SINTRAN/ND500/	README.md	ND-500 processor documentation
SINTRAN/TAD/	README.md	TAD protocol analysis

🚀 Use Cases

For Emulator Developers

→ Start at SINTRAN/Emulator/README.md

Understand SINTRAN kernel internals
Implement accurate hardware emulation
Access production C# code
Verify against actual NPL source

For System Archaeologists

→ Start at SINTRAN/OS/README.md

Study 1970s-1980s OS design
Analyze interrupt-driven architecture
Learn paging and virtual memory
Understand multi-CPU coordination

For Software Developers

→ Start at Developer/README.md

Learn SINTRAN development
Choose your language (8 languages supported)
Access complete reference manuals
Follow practical examples

For Hardware Analysts

→ Start at SINTRAN/Devices/README.md

Understand device driver architecture
Analyze communication protocols
Study HDLC and SCSI implementations
Access chip-level specifications

🗺️ Project Roadmap

✅ Completed (Phase 1)

Core kernel documentation (Chapters 00-19)
HDLC protocol analysis (consolidated)
SCSI subsystem analysis
ND-500 integration guide
TAD protocol documentation
NPL source code organization
Symbol table documentation
C# emulator code

🚧 Current Focus

Developer guide improvements
Cross-reference validation
Documentation accessibility

📋 Planned (Phase 2)

Monitor calls comprehensive guide
XMSG development guide
File system analysis (from symbols)
Additional device drivers
Build system analysis (MODE files)

🤝 Contributing

This repository is a work in progress. Areas for contribution:

Additional SINTRAN subsystem analysis
Emulator bug fixes and improvements
Protocol trace analysis
Hardware documentation
Historical information and context

📜 License

Documentation: Creative Commons Attribution 4.0 International (CC BY 4.0) Code: MIT License

🙏 Acknowledgments

Norsk Data AS - Original SINTRAN III development (1970s-1980s)
SINTRAN Source Code - Foundation for this analysis
Hardware Manuals - Official Norsk Data documentation
Emulator Community - Keeping vintage computing alive

Last Updated: 2025-11-06 Repository Version: 1.0 Documentation Status: Phase 1 Complete ✅

Preserving the legacy of Norsk Data computing through comprehensive technical analysis and documentation.

Name		Name	Last commit message	Last commit date
Latest commit History 88 Commits
Developer		Developer
Operations		Operations
Reference-Manuals		Reference-Manuals
SINTRAN		SINTRAN
ANALYSIS-REPORT.md		ANALYSIS-REPORT.md
MERMAID_COLOR_STANDARDS.md		MERMAID_COLOR_STANDARDS.md
README.md		README.md
test-output.md		test-output.md

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