O-Letto Novelty Co.
No date recorded
OBA, Inc. [Dallas, TX, USA]
No date recorded
OBC [Japan]
No date recorded
OES Corp.
No date recorded
OFA [Paris, France]
No date recorded
OHMCO Inc. [New Mexico, USA]
No date recorded
OMI Gaming
No date recorded
OPC Soft. [Japan]
No date recorded
OZ Corp.
No date recorded
Oakwood Publishing
No date recorded
Odrex [Odessa, Ukraine]
No date recorded
Ohio Match Co. [OH, USA]
No date recorded
Old Skool Studios
No date recorded
Olde N.Y. Amusement Factory [USA]
No date recorded
Olympic Games Mfg. Co.
No date recorded
Olympical
No date recorded
Omanuke Soft. [Japan]
No date recorded
On-Line Design, Inc.
No date recorded
One-Use Toothbrush Corp. [Van Nuys, CA, USA]
No date recorded
Onoe Network
No date recorded
Onslow Comtek
No date recorded
Onuma Denki Shoukai [Japan]
No date recorded
Open Corp.
No date recorded
Operasturias El Nene, S.A.
No date recorded
Operators Guide
No date recorded
Operators Supply Co.
No date recorded
Operomatic Video, S.A.
No date recorded
Opportunities For Learning
No date recorded
Opus Ent., Ltd. [Surrey, England]
No date recorded
Orbit Electronics
No date recorded
Orbyte Soft.
No date recorded
Ordividuel
No date recorded
Orel [Ukraine]
No date recorded
Oric Enthusiast
No date recorded
Oricsoft
No date recorded
Original Machine Co.
No date recorded
Orijon Soft.
No date recorded
Orkim Data
No date recorded
Oryx Gaming
No date recorded
Osborne & Associates, Inc.
No date recorded
Osmagyar Soft.
No date recorded
Otik [Japan]
No date recorded
Ottery, Darren
No date recorded
Overpriced Soft.
No date recorded
Ozarka, Ron
No date recorded
