Monthly Archives: September 2014

Installing Windows 95 on SCSI in a VM

For the adventurous, it is possible to install Windows 95 in a VM configured with SCSI storage (hard disk, CD-ROM) attached to an emulated BusLogic HBA. This works in VirtualBox, but there’s a catch—the emulated PCI BusLogic HBA must have … Continue reading

Posted in BusLogic, SCSI, VirtualBox, Windows 95 | 3 Comments

Forward Compatibility, Landmines

Several years ago, after attempting to get a very old 286 version of Xenix running in a VM, I concluded that it was probably incompatible with any 386 and later processor. Recently I revisited this issue and examined the problem … Continue reading

Posted in 286, Intel, Xenix | 29 Comments

386 Memory Managers and DMA

A while ago I ran into an odd problem: A virtual machine running QEMM 9.0 (aka QEMM 97) would crash more or less every time it tried to read something from a floppy. No such problem was observable in any … Continue reading

Posted in 386, Bugs, DOS, PC hardware | 7 Comments

Floating-Point Exceptions and DOS Extenders

Recently I had a need to test the behavior of floating-point exceptions (FPEs) in environments where traditional FPE reporting is used. To briefly recap, in the original PC equipped with an 8088/8087 pair, floating-point exceptions, which are generally asynchronous events, were … Continue reading

Posted in 386, Bugs, DOS, DOS Extenders, PC architecture | Leave a comment