Early Problems
Intel originally intended for the 80386 to debut at 16 MHz. However, due to poor yields, it was instead introduced at 12 MHz.
Early in production, Intel discovered a bug that could cause a system to unexpectedly halt when running 32-bit software. Not all of the processors already manufactured were affected, so Intel tested its inventory. Processors that were found to be bug-free were marked with a double-sigma (ΣΣ), and affected processors were marked "16 BIT S/W ONLY". These latter processors were sold as good parts, since at the time 32 bit capability was not relevant for most users. Such chips are now extremely rare.
The i387 math coprocessor was not ready in time for the introduction of the 80386, and so many of the early 80386 motherboards instead provided a socket and hardware logic to make use of an 80287. In this configuration the FPU would operate asynchronously to the CPU, usually with a clock rate of 10 MHz. The original Compaq Deskpro 386 is an example of such design. However, this was an annoyance to those who depended on floating point performance, as the performance of the 287 was nowhere near that of the 387.
Read more about this topic: Intel 80386
Famous quotes containing the words early and/or problems:
“I would observe to you that what is called style in writing or speaking is formed very early in life while the imagination is warm, and impressions are permanent.”
—Thomas Jefferson (1743–1826)
“I respect guilt. It is a dangerous but sometimes useful beast. The guilt that made me want to solve all my children’s problems meant trouble. The guilt that made me question my role in our mother-daughter squabbles proved helpful. Yes, I care about my kids’ problems, and I long to make suggestions. But these days I wait for children to ask for help, and I give it sparingly. Some things can’t be fixed, and I tell them so.”
—Susan Ferraro (20th century)