| ID | Name | Type |
|---|---|---|
| #1366 | Atari Inc | Z |
| #1367 | Atarisoft | P |
| #1368 | Ate Bit | ? |
| #22879 | Athena Software | P |
| #17052 | Athene Computers | H |
| #1369 | Atlantic Soft | Z |
| #17053 | Atlantic Supplies | S |
| #21020 | Atlantis | P |
| #17054 | Atlantis Games | S |
| #1370 | Atlantis Gold | Z |
| #1371 | Atlantis Software Ltd | M |
| #1372 | Atlas Adventure Software | Z |
| #16550 | Atom | + |
| #21925 | Atomic Projects | P |
| #1373 | Atomica | ? |
| #1374 | Atrox Programming Co | Z |
| #1375 | Attempto Verlag | ? |
| #1376 | Attila Kertesz | ? |
| #22907 | Audio Computing | Z |
| #1378 | Audio Visual Magic | Z |