Item #: SCP-155
Object Class: Safe
Special Containment Procedures: SCP-155 is to be stored in a secure containment chamber with a minimum of 30cm of lead-based radiation shielding. Experimentation with SCP-155 may only be performed with prior approval from at least two (2) Level 3 personnel, and no non-trivial computations may be performed with SCP-155 without explicit approval from at least one (1) Level 4 director. Experimentation must be performed within its containment chamber or other testing facility with similar radiation shielding, and personnel may not remain in the chamber while SCP-155 is operational. Non-halting algorithms must not be performed on SCP-155 at any time (see Addendum 155-01: Incident 155-A).
Description: SCP-155 is a smooth black cube measuring 28 cm x 28 cm x 28 cm weighing approximately 218 kg, composed of an unknown metallic substance known to contain lead, iridium, and [REDACTED], along with traces of other elements. It has no identifying markings or labels, and the density of its composite material has made scans of its interior impossible to date.
The "top" surface of SCP-155 exhibits a small, round indentation 2 cm in diameter. The "front" surface of SCP-155 exhibits two (2) 25-pin RS-232 serial ports and one (1) 2 cm diameter round push button, all of which is composed of the same material as the main body of SCP-155, with the exception of the RS-232 interface pins, which is composed of an unidentified silver material that exhibits [REDACTED] superconducting properties. At time of discovery, the upper RS-232 port was labelled "input" using masking tape and permanent marker, and the lower RS-232 port was labelled "output".
When a computer program is loaded into SCP-155 via its RS-232 interface and the button is pressed, SCP-155 begins executing the provided code. SCP-155's execution speed starts slow but increases asymptotically over time, approaching infinity as execution time approaches 8 minutes. As its speed increases, SCP-155 begins to "absorb" matter through its top indentation (presumably for use as "fuel") while at the same time emitting increasing amounts of heat and radiation, which increases proportionally with speed. While the radiation is negligible for almost all programs, the amount approaches dangerous levels as execution time exceeds 6 minutes and 30 seconds, and lethal dosages have been recorded over 7 minutes. Once execution is complete, SCP-155 writes the output via its second RS-232 port.
SCP-155 was discovered on █/██/██ in the remains of [REDACTED] in which SCP-155 was determined to have been the cause of the fire. At time of discovery, SCP-155 was plugged into a partially melted desktop computer, from which Foundation forensic investigators were able to recover enough data and code to create a compiler by which instructions for SCP-155 may be produced.
Addendum 155-01: Incident 155-A
On ██/█/██, Dr. ████ unintentionally input a non-halting program into SCP-155. After approximately 7 minutes and 58.3 seconds of execution, SCP-155 melted through its containment chamber, causing the destruction and total loss of the research area. Dr. ████ and █ others were killed, with an additional ██ research staff injured.
