> switching from real to protected mode is an exercise in doing every action in a long chain properly and in the right order or the whole undertaking fails Ver

> switching from real to protected mode is an exercise in doing every action in a long chain properly and in the right order or the whole undertaking fails Very true, and while the X86 is patch upon patch upon patch, in the designers defense, the intent on any 286+ Intel CPU was simply to was to use "real mode" to provide a bootstrap CPU to use to setup enough of the protected mode data tables to be able to actually enter protected mode. The intent was that entering protected mode was a one way, boot time only, street. Could they have made it simpler, maybe, but they were also viewing it as a one time effort that once you got the switch implemented, you didn't need to touch that code again. [edit for clarification]