Inventory the control system
- Image disks and preserve installers, configuration, databases, licenses and dongle state.
- Map RS232/RS485, USB, PCI/ISA cards, parallel interfaces, network services and vendor controllers.
- Record OS, drivers, COM/slot assignments, permissions and startup sequence.
- Capture representative machine cycles, timing and fault/recovery behavior where authorized and safe.
- Identify safety interlocks and changes requiring equipment/vendor specialists.
A virtual machine can preserve user-space software but cannot automatically reproduce ISA hardware, kernel drivers, dongles or deterministic interface timing.
Stage and prove the replacement
| Like-for-like spare | Lowest software change, but hardware availability may remain fragile. |
|---|---|
| Virtualized application | Useful when interfaces can be passed through or moved to supported gateways. |
| Interface gateway | Moves serial/device timing away from the new PC while preserving protocol behavior. |
| Application replacement | Requires recovered requirements and verified machine-state behavior. |
Test offline or in a controlled maintenance window. Keep the original PC and a documented physical/software rollback path until production acceptance is complete.
Use legacy serial integration, hardware protocol analysis, industrial software repair and serial application development.