By 1993, the Intel 486 was entrenched into the market. Also, people were used to the traditional 80×86 naming scheme. Intel was busy working on its next generation of processor. It was not to be called the 80586, though. There were some legal issues surrounding the ability for Intel to trademark the numbers 80586. So, instead, Intel changed the name of the processor to the Pentium, a name they could easily trademark. They released the Pentium in 1993. The original Pentium performed at 60 MHz and 100 MIPS. Also called the “P5″ or “P54″, the chip contained 3.21 million transistors and worked on the 32-bit address bus (same as the 486). It has a 64-bit external data bus which could operate at roughly twice the speed of the 486.

The Pentium family includes the 60/66/75/90/100/120/133/150/166/200 MHz clock speeds. The original 60/66 MHz versions operated on the Socket 4 setup, while all of the remaining versions operated on the Socket 7 boards. Some of the chips (75MHz - 133MHz) could operate on Socket 5 boards as well. Pentium is compatible with all of the older operating systems including DOS, Windows 3.1, Unix, and OS/2. Its superscalar design can execute two instructions per clock cycle. The two separate 8K caches (code cache and data cache) and the pipelined floating point unit increase its performance beyond the x86 chips. It had the SL power management features of the i486SL, but the capability was much improved. It has 273 pins that connect it to the motherboard. Internally, though, its really two 32-bit chips chained together that split the work. The first Pentium chips operated at 5 volts and thus operated rather hotly. Starting at the 100MHz version, the requirement was reduced to 3.3 volts. Starting at the 75MHz version, the chip also supported Symmetric Dual Processing, meaning you could use two Pentiums side by side in the same system.

MMX was not the only improvement on the Pentium MMX. The dual 8K caches of the Pentium were doubled to 16 KB each. It also had improved dynamic branch prediction, a pipelined FPU, and an additional instruction pipe to allow faster instruction processing. With these and other improvements, the Pentium line of processor was extended even longer. The line lasted up until recently, and went up to 233 MHz. While new PCs with this processor are all but non-existent, there are many older PCs still using this processor and going strong.