Talk:Intel 80286
From Wikipedia, the free encyclopedia
and could run up to 12.5MHz.
I removed this, because I think that it is wrong, but I'm not sure. I believe that a 16MHz 80286 was pretty common, and my father said that his first computer had a 20MHz 286 CPU. Can anyone confirm or deny? -- Stephen Gilbert
UPDATE: I am sure. Check this page: http://www.pcguide.com/ref/cpu/fam/g2I80286-c.html -- Stephen Gilbert
- It seems there were 25MHz 286s too, though not from Intel. Crusadeonilliteracy
codenamed iAPX
I removed this because the 80286 was not codenamed iAPX. The iAPX was a completely different processor family developed by Intel in 1981. At first the family consisted of a two-chip general data processor, and a single-chip interface processor. Eventually Intel added a bus interface unit and a memory control unit. Please see a great iAPX website at http://www.brouhaha.com/~eric/retrocomputing/intel/iapx432/
Chris Thames mavroxur@hotmail.com
[edit] Exiting protected mode
However, the 286 couldn't revert to real mode, so protected mode wasn't widely used until the appearance of the 386, which could go back and forth between modes.
It should be noted that although this is technically true, IBM and others created workarounds for this limitation early on, so it's not as big a problem as the article makes it sound.
References: Protected mode overview Triple-fault technique
Tim Peterson 18:03, 22 Apr 2005 (UTC)
[edit] The 80286's performance is more than twice that of its predecessors (the Intel 8086 and Intel 80186)
You know that section is pretty confused: The 80286 was perhaps twice as fast as it's predecessor, the 80186, because it typically ran at a higher clock speed. But it was much faster than the computer most people had, because like in the 80186, calculation of the more complex addressing modes (such as [BX+SI]) were performed by dedicated hardware; the widely used 8088 had microcoded intstructions (like a RISC processor) that took many clock cycles to complete. In fact, the performance increase per clock cycle between the 80186 and the 8086/8088 may be the largest among the generations of x86 processors. In comparison, (and speaking as one who used these processors) the step between the 80186 and the 80286 was negligable. On the other hand, I hate to say that you are just wrong: most people went straight from an 8MHz 8088 to a 16MHz 80286, and they were looking at a massive difference.
