- Enter on a signal entry (net / explore) opens a modal popup to pick power / gnd / other. Recording is deduped: a sequence of toggles on the same signal collapses to a single `set-signal-type` line; no-op selections record nothing. - Bare interactive commands (the ones that open a full-screen mode) are no longer recorded by `script-save`. Their inline forms still are. Mutating actions inside a screen record their own canonical line. - Mentor importer treats signals whose name starts with `unconnected` as no-connect — the pin is kept on the part without a signal and tagged `ImportedUnconnected`. - `drop_singleton_signals` runs at the end of `load`: any signal with exactly one pin is detached (singletons are NC by definition); the pin is tagged `DroppedSingleton`. Count is reported inline. - `verify` gains a one-line orphan summary (imported NC / dropped singleton totals). Pins materialised by `FillIdentityNCs` are excluded via a `pin_map` filter — they are bridged to a real signal on the peer module and are not real NCs at system level. - NcOrigin tag is serialized in save snapshots as an optional 4th field on N records (backward-compatible). Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
essim — system digital twin
Interactive simulator for the inter-card connections inside a system. Built around a domain model of modules → parts → pins / signals → connections, with importers for Mentor Graphics, Altium and ODS pinout sheets, a TUI shell with scripting, snapshots and BFS net analysis.
Status: early work-in-progress.
Quick start
cmake -S . -B build
cmake --build build -j
./build/essim
Requirements:
- A C++17 compiler.
- CMake 3.14+.
- System packages:
libzipandpugixml(Arch:pacman -S libzip pugixml). - FTXUI (v6.1.9) and doctest (v2.4.11) are fetched at configure time via
FetchContent.
Inside the shell, type help for the live command list — or read the
auto-generated reference at doc/user/commands.md.
A worked bring-up script is at test/system.essim;
load it with source test/system.essim.
Tests
./build/essim_tests
# or
ctest --test-dir build
Skip building tests entirely:
cmake -S . -B build -DBUILD_TESTING=OFF
Documentation
doc/user/— user guide, command reference, scripting.doc/api/— auto-generated C++ API reference.DESIGN.md— implementation notes (domain conventions, TUI internals, gotchas).doc/README.md— how the doc pipeline is wired.
Regenerate auto-generated parts after substantive code changes:
cmake --build build --target doc # needs doxygen + python3
Project layout
src/system/ domain model (Module/Part/Pin/Signal, Connection, Transform, …)
src/imports/ Mentor / Altium / ODS netlist importers
src/tui/ FTXUI shell (commands, screens, completion, history)
tests/ doctest suite
doc/ api/ + user/ Markdown trees, Doxyfile.in, gen_api_md.py
test/ sample netlists + system.essim bring-up script
Full layout & rationale in DESIGN.md.
Licence
Copyright (c) 2026 François Dausseur
Licensed under the European Union Public Licence (EUPL), Version 1.2 —
the "Licence". You may not use this work except in compliance with the
Licence. You may obtain a copy of the Licence in the LICENSE
file or at https://joinup.ec.europa.eu/software/page/eupl.
Unless required by applicable law or agreed to in writing, software distributed under the Licence is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the Licence for the specific language governing permissions and limitations under the Licence.
SPDX-License-Identifier: EUPL-1.2