Monthly Archives: May 2011

OS/2 2.0 Limited Availability

In October 1991, IBM released OS/2 2.0 “Limited Availability” (or LA) at the Fall Comdex in Las Vegas. This was a semi-official release of 32-bit OS/2, effectively a beta version, although it wasn’t called a beta. At the same Comdex, … Continue reading

Posted in NT, OS/2 | 14 Comments

The floppy controller evolution

The floppy subsystem in PCs hadn’t mutated over time quite as much as, say, the hard disk subsystem, but prior to its extinction in the early 21st century, the floppy disk controller (FDC) did evolve noticeably. In the original IBM … Continue reading

Posted in PC architecture | 4 Comments

Xenix 286 in a VM

The fixes which were included in VirtualBox 4.0.8 happen to help not only OS/2 1.x but also Xenix. The 386 versions of Xenix 2.3.x (not necessarily older versions!) should install in a VM without trouble, but the 286 versions are … Continue reading

Posted in VirtualBox, Xenix | 8 Comments

Installing OS/2 1.x in a VirtualBox VM

Installing 16-bit OS/2 in a virtual machine ranges between “tricky” and “impossible”, depending on the version of OS/2 and virtualization software used. In VirtualBox 4.0.8, things have moved further away from “impossible” and closer towards merely “tricky”. Version 4.0.8 fixed problems with floppy … Continue reading

Posted in OS/2, VirtualBox | 29 Comments

The Fixed Disk Parameter Table

The Fixed Disk Parameter Table, or FDPT, is a structure primarily used by the BIOS in IBM compatible computers, but is also of critical importance to some (especially older) operating systems which do not use the BIOS. The FDPT was … Continue reading

Posted in BIOS, PC architecture, Virtualization | 3 Comments

Geometry Problems

When introducing hard disk support in the PC/XT back in early 1983, IBM made a very unfortunate design decision: the information about drive geometry was exposed in the BIOS, and even worse, in the boot sector stored on the disk. SCSI … Continue reading

Posted in BIOS, PC architecture, Virtualization | Leave a comment