If you need PSpice compatibility without installation, consider these options:
While the convenience is tempting, downloading a pre-cracked portable from an unknown source carries significant risks: orcad pspice 16.3 portable
If you need circuit simulation without a heavy install: You can run it from a USB stick
| Tool | Portable? | Free? | Good for | |------|-----------|-------|----------| | LTspice | No (but lightweight) | Yes | Almost everything PSpice does | | Micro-Cap 12 | Yes (old version) | Yes (abandonware, legally free) | SPICE simulations | | Qucs-S | Yes (via portable apps) | Yes | RF and analog circuits | | Ngspice | Yes (command line) | Yes | Scripted simulation | then released as freeware.
Micro-Cap 12 is especially worth mentioning — it was commercial software, then released as freeware. You can run it from a USB stick.
