- O -

- Object Kernel for DOS
 - 
ODIHLP.EXE - INSTALLATION CHECK
 - Olivetti Quaderno
 - Omniview Multitasker
 - 
Ontrack Drive Rocket - SET CYLINDER OFFSET
 - 
OPTHELP.COM
 - 
OPTIMA 1024 VGA-Sync - QUERY ZOOM WINDOW
 - OPTIMA 1024 VGA-Sync,ET-3000 chipset
 - Oracle SQL Protected Mode Executive
 - OS HOOK
- 
COMPLETION OF SYSREQ FUNCTION (AT,XT286,PS50+)
 - 
DEVICE BUSY (AT,PS)
 - 
DEVICE CLOSE
 - 
DEVICE OPEN (AT,XT286,PS)
 - 
DEVICE POST (AT,PS)
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PROGRAM TERMINATION
 - 
ROM BIOS TRACING CALLOUT (PS30/286,PS50Z,PS95)
 - 
SETUP SYSREQ ROUTINE (AT,XT286,PS50+)
 - 
OS HOOK - SysReq KEY ACTIVITY (AT,PS)
 
 - 
OS/2 - GET VDD API ENTRY POINT
 - OS/2 compatibility box
 - 
OS/2 v1.1+ Compatibility Box Family API - DosQPathInfo
 - OS/2 v1.1+ Family API
 - OS/2 v1.x FAPI
 - 
OS/2 v2.0 - DosOpen2
 - 
OS/2 v2.0+ - INSTALLATION CHECK / GET VERSION
 - OS/2 v2.0+ Virtual DOS Machine
 - 
OS/2 v2.1 Virtual DOS Machine - GET LASTDRIVE
 - OS/2 v2.1+ Virtual DOS Machine
 - OS/286, OS/386
 - OS/386 VMM
 - 
Overlay manager interrupt (Microsoft LINK.EXE, Borland TLINK VROOMM)
 - 
Overwritten by CP/M jump instruction in INT 30
 
