| Atari Football (4 players) (clone of: atarifb) | 1979 | Atari | atarifb4 | Sports / Football Amer. | 0.00 |
| Atari Football (revision 1) (clone of: atarifb) | 1978 | Atari | atarifb1 | Sports / Football Amer. | 0.00 |
| Atari Football (revision 2) | 1978 | Atari | atarifb | Sports / Football Amer. | 5.75 |
| Atari Mini Golf (prototype) | 1978 | Atari | mgolf | Sports / Golf | 0.00 |
| Atari PSX | 1996 | Atari | atpsx | BIOS | 3.29 |
| Atari Soccer | 1980 | Atari | soccer | Sports / Soccer | 4.67 |
| Atari System 1 BIOS | 1984 | Atari Games | atarisy1 | | 0.00 |
| Ataxx (Europe) (clone of: ataxx) | 1990 | Leland Corp. | ataxxe | | 0.00 |
| Ataxx (Japan) (clone of: ataxx) | 1990 | Leland Corp. | ataxxj | Tabletop | 0.00 |
| Ataxx (set 1) | 1990 | Leland Corp. | ataxx | Tabletop | 2.02 |
| Ataxx (set 2) (clone of: ataxx) | 1990 | Leland Corp. | ataxxa | Tabletop | 0.00 |
| Athena | 1986 | SNK | athena | Platform / Fighter Scrolling | 7.30 |
| Athena no Hatena ? | 1993 | Athena | atehate | Quiz / Japanese | 0.00 |
| Atlant Olimpic (clone of: trackfld) | 1996 | bootleg | atlantol | Sports / Track & Field | 0.00 |
| Atlantic (Vivid) (MPU5, v1.2) (clone of: m5atlan) | 1969 | Vivid | m5atlana | | 0.00 |
| Atlantic (Vivid) (MPU5, v1.4) | 1969 | Vivid | m5atlan | | 0.00 |
| Atlantic City Action (clone of: bwcasino) | 1983 | Epos Corporation | acitya | Casino | 0.00 |
| Atlantica (Russia) (Atronic) (set 1) | 2002 | Atronic | atlantca | | 0.00 |
| Atlantica (Russia) (Atronic) (set 2) (clone of: atlantca) | 2002 | Atronic | atlantcaa | | 0.00 |
| Atlantis | 1989 | Bally | atlantip | | 0.00 |