Qucs-S integration (Windows)

September 2, 2026 · View on GitHub

LibMan runs on Windows. Qucs-S (CORE-enabled) also runs natively on Windows — no WSL. Double-click a schematic/symbol view → run-qucs-s.bat → Qucs-S opens the .schematic.core / .symbol.core file. Simulation is done inside Qucs-S (Simulate → ngspice).

Xschem (WSL) remains available as a second schematic tool — see Xschem integration.

Overview

LibMan (Windows)
  double-click schematic / symbol
    → run-qucs-s.bat
      → qucs-s.exe <path>
        → load *.schematic.core / *.symbol.core (CORE bridge)
        → Simulation → ngspice_con.exe

View in LibMan	File suffix	Tool
`schematic`	`*.schematic.core`	Qucs-S or Xschem (pick in Tool Manager / multi-tool)
`symbol`	`*.symbol.core`	same
`layout`	`*.layout.core`	KLayout

Prerequisites

Qucs-S (CORE build)

Checkout and build sibling to CommonDB/LibMan:

parent/
  Qucs-S-coredb/   ← https://github.com/adatsuk/Qucs-S-coredb
  CommonDB/
  LibMan/
  XSchem-coredb/   ← optional second schematic tool

Build notes: Qucs-S-coredb/docs/CORE.md. Expect:

Qucs-S-coredb\build\qucs\qucs-s.exe
Qucs-S-coredb\run-qucs-s.bat

ngspice (Windows)

Qucs-S needs ngspice_con.exe on PATH (console binary, not the GUI ngspice.exe).

Recommended for IHP OSDI on Windows: ngspice-46 (OSDI v0.4) with PE plugins in osdi-win/.

run-qucs-s.bat prefers, if present:

%USERPROFILE%\Documents\VBIC_cryo\tools\ngspice\Spice64\bin\ngspice_con.exe

Fallback: ngspice-42 under %USERPROFILE%\Spice64\… (OSDI v0.3 only — needs matching older PE plugins).

IHP Open-PDK models + Qucs libraries

Models / OSDI (for .LIB cornerMOSlv.lib mos_tt):

Primary models path (this machine):

C:\Work\IHP\ihp-sg13g2\libs.tech\ngspice\models\

Fallback / WSL copy:

%USERPROFILE%\Documents\IHP-Open-PDK\ihp-sg13g2\libs.tech\ngspice\models\
%USERPROFILE%\Documents\IHP-Open-PDK\ihp-sg13g2\libs.tech\ngspice\osdi\

User spiceinit — %USERPROFILE%\.spiceinit must set sourcepath to the models directory and load Windows OSDI plugins.

The files under …/ngspice/osdi/ in the PDK tree are usually Linux ELF. On Windows they fail with
%1 is not a valid Win32 application.
Put PE (Windows) builds in …/ngspice/osdi-win/ (compile with OpenVAF from an x64 Native Tools prompt, or copy known-good PE plugins).
Qucs user libraries — %USERPROFILE%\.qucs\user_lib\:
```
IHP_PDK_nonlinear_components.lib
IHP_PDK_basic_components.lib
IHP_PDK_stdcells.lib
```
Source in PDK: ihp-sg13g2/libs.tech/qucs-s/user_lib/.
run-qucs-s.bat copies them once if missing and PDK_ROOT is set.

Example %USERPROFILE%\.spiceinit:

setcs sourcepath = ( $sourcepath C:/Work/IHP/ihp-sg13g2/libs.tech/ngspice/models )

osdi 'C:/Users/<you>/Documents/IHP-Open-PDK/ihp-sg13g2/libs.tech/ngspice/osdi-win/psp103.osdi'
osdi 'C:/Users/<you>/Documents/IHP-Open-PDK/ihp-sg13g2/libs.tech/ngspice/osdi-win/psp103_nqs.osdi'
osdi 'C:/Users/<you>/Documents/IHP-Open-PDK/ihp-sg13g2/libs.tech/ngspice/osdi-win/r3_cmc.osdi'
osdi 'C:/Users/<you>/Documents/IHP-Open-PDK/ihp-sg13g2/libs.tech/ngspice/osdi-win/mosvar.osdi'

Build Windows OSDI (once), from libs.tech/verilog-a/… with OpenVAF on Windows + MSVC x64 linker, e.g.:

cd %PDK_ROOT%\ihp-sg13g2\libs.tech\ngspice\osdi-win
openvaf ..\..\verilog-a\psp103\psp103.va

LibMan Tool Manager

Settings → Tools:

Field	Value
Tool name	e.g. `qucs` or reuse `schematic`
Executable	Full path to `run-qucs-s.bat`
Name(s)	`schematic` (and optionally `symbol`)

Example:

C:\Users\anton\Documents\Qucs-S-coredb\run-qucs-s.bat

If both Xschem and Qucs are registered for schematic, LibMan will ask which tool to use on open.

Do not put open-xschem-wsl.sh next to this .bat — LibMan prefers the WSL launcher when that script sits beside the chosen bat.

What LibMan passes

Same primitive env as Xschem (projectfile.cpp):

Variable	Purpose
`CORE_PRIMITIVE_LIBS_FILE`	List of `*.symbol.core` (design + tech)
`LIBMAN_TECH_LIBRARY`	Library names
`QUCS_PRIMITIVE_LIB`	`IHP_PDK_nonlinear_components` (Qucs `<Lib>` bundle)

Qucs-S CORE load uses PrimitiveResolver + skips Xschem-only decorations (code_shown, launcher, …).

Simulation tips

Open a Qucs-native TB (has .TR / .DC + INCLSCR + Lib / CORE hierarchy) — not only an Xschem TB that relied on code_shown NGSPICE blocks.
In Qucs-S: check Simulation → Simulators Settings → Ngspice = ngspice_con.exe (or full path under Spice64\bin).
Press Simulate (F2 / toolbar). Plots use diagram nodes like ngspice/v(vout).

Smoke tests

Schematic	Path
Official IHP DC NMOS	`IHP-Open-PDK/.../libs.tech/qucs-s/examples/dc_lv_nmos.sch` (File → Open)
LibMan Qucs examples	`LibMan/tests/data/Qucs_examples/dc_lv_nmos/dc_lv_nmos.schematic.core`
Flat inverter TB (Qucs)	`LibMan/tests/data/_invcheck/inverter_tb_qucs_sim.sch`

Xschem inverter_tb.schematic.core opens in Qucs but drops NGSPICE code_shown — add a Qucs .TR + INCLSCR (or use the flat TB above) before Simulate works like Xschem.

Troubleshooting

Symptom	Fix
`qucs-s.exe` missing	Build Qucs-S-coredb (`docs/CORE.md`)
Ngspice not found	Install ngspice-42; ensure `ngspice_con.exe` on PATH via `run-qucs-s.bat`
`cornerMOSlv.lib` not found	Set `.spiceinit` `sourcepath` + copy PDK `models/`
OSDI `%1 is not a valid Win32 application`	PDK `osdi/*.osdi` are Linux ELF — use `osdi-win/` PE builds in `.spiceinit`
Empty / missing Lib components	Install `~/.qucs/user_lib/IHP_PDK_*.lib`
Hierarchy missing pins	Attach tech/design libs in LibMan so `CORE_PRIMITIVE_LIBS_FILE` is set

Xschem integration — WSL schematic path
Import — qucs_to_core / core_to_qucs
CORE integration
Qucs-S CORE notes: Qucs-S-coredb/docs/CORE.md