This was a group assignment for our Operating Systems module. Our group was asked to present on IBM's operating system, OS/2. My role was to research the architecture behind OS/2

1. User Layer
• Compatibility with OS/2, Windows 3.0 and DOS
applications
• App compatibility achieved using a Virtual DOS Machine
(VDM)
• VDM allowed the apps to run alongside another OS

2. Presentation Manager
• The GUI of OS/2
• Supports mouse chording
• Follows IBM’s Common User Access (CUA) interface
standard
• Operates using a Single Input Queue (SIQ)

3. Issues with Single Input Queue
• Blocked by a single unresponsive application
• Caused the user interface to freeze
• Never properly addressed and fixed

4. Kernel Layer
• Boot manager handles improper boot procedures
• Handles process switching by rewriting and reallocating
memory
• Memory is allocated in 64Kb pieces
• Virtual device drivers exist outside the kernel
• Each shutdown iteration occurs in two parts