| ID | Name | Type |
|---|---|---|
| #296 | ARDENT Software | Z |
| #297 | AREAsoft | Z |
| #23104 | ARP | + |
| #298 | ARP Software | Z |
| #299 | ART | ? |
| #17961 | ASAP Developments | Z |
| #300 | ASB | ? |
| #22378 | ASC | P |
| #301 | ASCII | ? |
| #302 | ASF | ? |
| #303 | ASK Software | Z |
| #17018 | ASM Software | S |
| #17019 | ASN Computers | S |
| #22411 | ASP Hackers Club | P |
| #304 | ASP Software Ltd | P |
| #305 | ASW | ? |
| #21275 | AT Computer Systems | Z |
| #306 | AT&Y Computing Ltd | Z |
| #18382 | ATM | P |
| #307 | ATVS | ? |