Original Core

The original Core brand refers to Intel's 32-bit mobile dual-core x86 CPUs that derived from the Pentium M branded processors. The processor family used a more enhanced version of the Intel P6 microarchitecture. It emerged in parallel with the NetBurst microarchitecture(Intel P68) of the Pentium 4 brand, and was a precursor of the 64-bit Core microarchitecture of Core 2 branded CPUs. The Core brand comprised two branches: the Duo (dual-core) and Solo (Duo with one disabled core, which replaced the Pentium M brand of single-core mobile processor).

The Core brand was launched on January 6, 2006 by the release of the 32-bit Yonah CPU – Intel's first dual-core mobile (low-power) processor. Its dual-core layout closely resembled two interconnected Pentium M branded CPUs packaged as a single die (piece) silicon chip (IC). Hence, the 32-bit microarchitecture of Core branded CPUs – contrary to its name – had more in common with Pentium M branded CPUs than with the subsequent 64-bit Core microarchitecture of Core 2 branded CPUs. Despite a major rebranding effort by Intel starting January 2006, some computers with the Yonah core continued to be marked as Pentium M.

The Core series is also known for being the first Intel processor to be used as the main CPU for an Apple Macintosh computer. The Core Duo was the CPU for the first generation MacBook Pro while the Core Solo appeared in Apple's Mac mini line. Core Duo signified the beginning of Apple's shift to Intel processors across their entire line.

In 2007, Intel began branding the Yonah core CPUs intended for mainstream mobile computers as Pentium Dual-Core, not to be confused with the desktop 64-bit Core microarchitecture CPUs also branded as Pentium Dual-Core.

September 2007 and January 4, 2008 mark the discontinuation of many Core branded CPUs.