A PC with specialized flashing software (like BwE’s PS4 Syscon Tools). The Risks Involved
Tools like a Teensy ++ 2.0 or a TNC (Tiny Jumper Cable) are used to read and write the chip data.
The Syscon chip acts as the console's gatekeeper. To downgrade, the chip must be glitched or patched to "forget" its current version check.
This is a high-stakes modification that carries a significant risk of permanently "bricking" (disabling) the console.
. It typically requires complex hardware modifications, such as soldering and using an external programmer to revert the console's "syscon" chips
The PS4 Slim's hardware was slightly downgraded, with a 1.6 GHz x86-64 AMD Jaguar 8-core processor, 8 GB of GDDR5 RAM, and a 1.84 TFLOP AMD Radeon Graphics Core Next engine. However, the console's GPU was slightly less powerful than the original PS4, with a reduced clock speed.
There is a small chance that in 2–3 years, a plug-and-play downgrade device will hit the market. Until then, treat every “software downgrade” claim as fiction.
If you're looking for specific features or functionalities not available on the latest firmware: