for the data path and 8 bits used for error correcting code (ECC). The memory interface unit manages the bus and performs ECC checks on data coming into the processor. The ECC logic is capable of correcting single-bit errors. Compared to the POWER1, the RSC memory data bus is narrower and uses industry standard SIMMs instead of custom memory cards. The RSC contained approximately one million transistors on a 14.9 mm by 15.2 mm (226.48 mm2) die fabricated by IBM in a complementary metal-oxide semiconductor (CMOS) process with a minimal feature size of 0.8 μm and three levels of wiring. It is packaged in a 36 mm by 36 mm ceramic pin grid array module which had 201 signal pins. It required a 3.6 volt power supply and consumed 4 watts during operation at 33 MHz. See also PowerPC 601 which essentially was a cheaper and less powerful version of RSC with some PowerPC instructions added. RAD6000 which is a radiation hardened version of RSC. References IBM microprocessors