Change Nonstop Code with Confidence
In a legacy Nonstop environment, every change carries hidden risk. A modified program can break callers you didn't know existed. A changed file layout can silently corrupt programs across the system. A renamed field can ripple through copybooks, paragraphs, and data flows in ways no one has documented in years.
Navigator Atlas answers the questions you need answered before you touch anything. It performs deterministic static analysis of your COBOL, TAL, and SCOBOL source - mapping every call path, every file access, every field reference — and gives you a complete impact picture in seconds.
Impact Analysis
Four questions. Answered instantly. Scan your source folder once. Select any program, file, or field. Get the full picture.
1. Program Change Impact
If I change a program, what other programs could be affected? Atlas traces direct callers (programs that CALL or PERFORM this one), transitive callers (everything upstream in the call chain), and programs sharing files with it giving you the full blast radius before you write a single line.
2. Dependencies
What libraries, files, and copybooks does this program touch? The Copybooks, Files, and Tables axes of the Impact view show every dependency this program has — and flip the question: select a copybook to see every program that includes it. 53 copybooks, 27 programs - mapped in one screen.
3. File Layout Changes
If I change a file layout, what programs will be affected? The Dependency Matrix → File→Programs view lists every file in the system and, for each file, every program that reads or writes it—with the exact CRUD operations (Create, Read, Update, Delete) each paragraph performs. No guessing. No grepping. Atlas already knows.
4. Field Ripple Effects
If I change a field in a file, what are the ripple effects? The Field XRef traces every variable defined in a file's record layout and shows exactly which paragraphs reference it — with line numbers, type, and usage count. Click a field to see the paragraph details: what it calls, what decisions it makes, what it reads and writes.
More Than Impact
Full program understanding and analysis capabilities built in.
Program Structure
Cyclomatic complexity per paragraph, nesting depth, dead code detection, and comprehensive line metrics.
Call Graph
Interactive force-directed graph of PERFORM, CALL, SEND, ENTER TAL, and GO TO edges. Zoom and filter by depth.
Step-Through Simulator
Walk code line by line, choose branches at IF/EVALUATE, and trace execution paths without compiling.
Screen Layout Preview
Renders SCOBOL SCREEN SECTION as a terminal preview. See the 6530 screen directly from source.
Quality Analysis
Flags complexity hotspots, uninitialized data, unused variables, and deep nesting. Risk-ranked folder dashboard.
HTML Export
Export self-contained HTML reports for any program or folder. Share with anyone — no Atlas install needed.
Supported Languages
Comprehensive language support with varying analysis depths.
| Language | Analysis Depth | Impact Analysis Support |
|---|---|---|
| COBOL | Full | Program callers, file CRUD, field XRef, copybook dependencies |
| SCOBOL (Screen COBOL) | Full + screens | All COBOL impact features plus screen field cross-reference |
| TAL | Full | PROC callers, Guardian file I/O, ?SOURCE include chain |
| TACL | Structure | Routine extraction and call structure |
What Navigator Atlas Delivers
| Capability | What You Get |
|---|---|
| Change Impact Analysis | ✓ Full blast radius — callers, files, fields, copybooks |
| Cross-program Call Graph | ✓ Every CALL, PERFORM, SEND edge traced |
| Dependency Matrix | ✓ Programs × files CRUD matrix across entire codebase |
| Field Cross-Reference | ✓ Every field tracked from definition to every paragraph that uses it |
| Results Consistency | ✓ Deterministic — identical results every run |
| Deployment | ✓ Self-contained, runs on-premises, no external dependencies |
Technical Specifications
Platform
Windows 10/11 (64-bit)
Runtime
Self-contained, no .NET install required
Interface
Browser-based (Chrome, Edge, Firefox)
Network
Offline, SFTP only for remote file browse
Analysis Engine
Deterministic—consistent results, no cloud dependency
Output
Interactive web UI + exportable HTML reports
Ready to Know the Impact?
See Navigator Atlas in action. Get a personalized demo tailored to your Nonstop environment.
Request a Demo