O-Pen - see aolpen
Object, 292
Object Oriented Programming - see boopsi
Object Oriented Programming System for Intuition - see boopsi
ObtainConfigBinding(), 759
ObtainGIRPort(), 319, 323, 330
ObtainSemaphore(), 512, 513, 513, 514, 514, 515
ObtainSemaphoreList(), 510, 514, 515
ObtainSemaphoreShared(), 513, 515
OFF_DISPLAY, 610
OffGadget(), 130, 166
OffMenu(), 185, 189, 191, 200
OM_ADDMEMBER, 302, 307
OM_ADDTAIL, 307
ON_DISPLAY, 610
OM_DISPOSE, 307 - see also appendix b and disposeobject()
OM_GET, 307, 311 - see also appendix b and getattr()
OM_NEW, 307, 308 - see also appendix b and newobject()
OM_NOTIFY, 307, 309
OM_REMMEMBER, 307
OM_REMOVE, 307
OM_SET -->
OM_UPDATE, 307, 309 - boopsi gadgets, 298
OnGadget(), 130, 166
OnMenu(), 185, 189, 191, 200
Open vector, 437
Open(), 263
OpenClipboard(), 781, 810
OpenDevice(), 447
OpenDiskFont(), 188, 243, 670, 675
OpenFont(), 243, 670, 675
OpenIFF(), 344, 782, 810
Opening a device, 447
OpenLibrary(), , , 188, 263, 435
OpenMonitor(), 568, 611
OpenScreen(), 42, 43, 45, 46, 76
OpenScreenTagList(), 42, 45, 45, 46, 53, 56, 59, 76
OpenScreenTags(), 42, 42, 45, 46, 76
OpenWindow(), 80, 115
OpenWindowTagList(), 53, 80, 82, 83, 85, 90, 92, 92, 93, 97, 98, 104, 107,
                     107, 108, 115, 175, 249, 254
OpenWindowTags(), 80, 115
OpenWorkBench(), 52-53, 76
opGet structure, 311
opMember structure, 303
opSet structure, 305, 308
Optimized Refresh - layers, 705, 711, 719
OPUF_INTERIM, 309
opUpdate structure, 309
OrRectRegion(), 722
OrRegionRegion(), 722
OSCAN_MAX, 62
OSCAN_STANDARD, 62
OSCAN_TEXT, 62, 86
OSCAN_VIDEO, 62
OSERR_NOCHIPMEM, 45
OSERR_NOCHIPS, 45
OSERR_NOMEM, 45
OSERR_NOMONITOR, 45
OSERR_PUBNOTUNIQUE, 45
OSERR_UNKNOWNMODE, 45
Outline mode - in Flood() fill, 591
Outline pen, 584
Output -->
Overscan -->
OverscanPrefs structure, 339
OwnBlitter(), 599, 599, 612