| Type | Game | Year | Publisher |
|---|
|
| DEC PDP-5 soft. | OPAK [No. 5-2.1] | 1965 | DECUS [Digital Equipment Computer Users' Society] |
|
| IBM PC/AT DOS 3.5in. disk | Operation Crusader | 1994 | Avalon Hill Video Game Co., The [Baltimore, MD, USA] |
|
| Atari Falcon 030 disk | Operation SKUUM | 1996 | Logitron |
|
| Arcade Video game | Operation Thunderbolt | 1988 | Taito Corp. [Japan] |
|
| Arcade Video game | Operation Wolf | 1987 | Taito Corp. [Japan] |
|
| Apple Macintosh disk | Operation: Desert Storm | 1991 | Bungie Soft. |
|
| PC/MS-Windows CD | Operation: Weather Disaster | 1995 | Discovery Channel Multimedia |
|
| Dick Smith Super-80 cass. | Opposites [Model 064L4] | 198? | Unknown |
|
| Arcade Video game | Orbs | 1994 | American Sammy Corp. [Torrance, CA, USA] |
|
| PTC SOL-20 cass. | Oregon | 1978 | Hopkins, Ralph |
|
| Commodore VIC-20 type-in | Organ | 1984 | Granada Publishing |
|
| Tangerine Oric 1 cass. | Oric Flight | 1983 | Tansoft |
|
| Tangerine Oric 1 cass. | Oricmunch | 1983 | Tansoft |
|
| IGS PGM cart. | Oriental Legend | 1997 | IGS Co., Ltd. [International Game System] |
|
| PLATO soft. | Orthanc | 1975 | Resch & Kemp & Hagstrom |
|
| RCA COSMAC VIP type-in | Ortho | 1980 | Association of Computer Experimenters |
|
| Atari 2600 cart. | Oscar's Trash Race [Model CX26101] | 1983 | Atari, Inc. [CA, USA] |
|
| Arcade Video game | Oshaberi Macha Monoshiri Quiz | 1983 | Logitec Co., Ltd. |
|
| Nintendo Super Famicom cart. | Osu!! Karate-bu [Model SHVC-OJ] | 1994 | Culture Brain |
|
| Thomson TO7 type-in | Othello | 1984 | Shift Editions [Paris, France] |
|
| Bally Astrocade cass. | Othello | 198? | Perkins & Brigden |
|
| Casio PB-100 type-in | Ougon'noken | 1985 | Dempa Shinbunsha [Japan] |
|
| Commodore VIC-20 type-in | Our First Game Program | 1983 | NET Soft. |
|
| Amstrad CPC 464 disk | Out Board | 1990 | Loriciels [France] |
|
| DEC PDP-7 soft. | OUTFLT [No. 7-23] | 1966 | DECUS [Digital Equipment Computer Users' Society] |
|
| Sega Mega Drive cart. | OutRun 2019 [Model T-44033] | 1993 | SIMS Co., Ltd. [Japan] |
|
| Nintendo Famicom cart. | Over Horizon [Model GAM-Z6] | 1991 | Hot-B [Japan] |
|
| SNK Neo-Geo MVS cart. | Over Top | 1996 | ADK Corp. [Japan] |
|
| Sony PlayStation CD-ROM | OverBlood [Model SLPS-00392] | 1996 | Riverhill Soft. [Japan] |
|
| Bally Astrocade type-in | P.T.O. X-mass | 198? | Fabris, Robert [San Jose, CA, USA] |
|
| Sega Game Gear cart. | Pac-In-Time | 199? | NAMCO, Ltd. [Japan] |
|
| HP-48SX soft. | Pac-Man | 1991 | De Dinechin, Christophe |
|
| HP-39/40 soft. | Pac-Man | 2000 | Pigallio, Lilian |
|
| HP-49 soft. | Pac-Man | 2000 | Pigallio, Lilian |
