Category Archives: x86

Solaris 2.5.1 and 2.6 crashes on modern Intel CPUs

I recently found that Solaris 2.6 and 2.5.1 does not work when run in a VM on a modern Intel CPU (Sandy Bridge generation Core i7), or to be exact fails most of the time (about nine times out of … Continue reading

Posted in Solaris, VirtualBox, Virtualization, x86 | 27 Comments

64-bit trouble with Solaris 10 U4 and earlier

On many newer systems, Solaris 10 releases up to and including Solaris 10 8/07 (that is Update 4, also known as S10U4)┬ábehave in an unhelpful manner. The installer can be launched from CD or DVD and the system can be … Continue reading

Posted in Solaris, x86 | 12 Comments

AVX support disrupts WoW64 debugging

Sometimes, the old and the new intersect in unexpected ways. After upgrading to a Sandy Bridge based system (Core i7) and Windows 7 SP1 64-bit some time ago, I noticed that debugging exceptions in 32-bit user programs didn’t quite work … Continue reading

Posted in Windows, x86 | 18 Comments

DOS Memory, Managers & Extenders, Part I

To understand why the maddeningly complex world of DOS memory managers and extenders came to be, it’s necessary to understand the evolution of the PC platform. Even though memory managers and DOS extenders reached their peak on 32-bit 386 and … Continue reading

Posted in DOS, PC architecture, PC history, x86 | 27 Comments

HIMEM.SYS, unreal mode, and LOADALL

The previous post talked about real mode on 286+ processors which behaves more like a slightly modified variant of protected mode rather than the old 8088/8086 processors. Real mode with non-compatible selector bases or limits is usually called unreal mode … Continue reading

Posted in DOS, x86 | 3 Comments

Will the real Real Mode please stand up?

Every programmer familiar with the x86 architecture understands the difference between real and protected address mode of the processor. It is well known that the real mode is compatible with Intel’s old 16-bit 8088/8086 CPUs, while protected mode was a … Continue reading

Posted in x86 | 3 Comments