Configuration with Modem Installed by Apple
| Part Number And Description | Last 3 Digits Of Serial Number |
| M3120LL/A CPU PowerBook 540 12/240 | 2SZ |
| M3121LL/A CPU PowerBook 540c 12/320 | 2T0 (0=zero) |
Configuration Without Modem
| Part Number And Description | Last 3 Digits Of Serial Number |
| M2807LL/A CPU PowerBook 540 4/240 | 28Q |
| M2809LL/A CPU PowerBook 540c 4/320 | 28V |
| M1845LL/A CPU PowerBook 520 4/160 | 154 |
| M2597LL/A CPU PowerBook 520c 4/160 | 1XN |
How to distinguish a modem if it has been removed from the PowerBook:
A modem which was configured at the Apple factory will have a small Apple logo on the modem and the DAA.
A modem that was purchased retail will NOT have the Apple logo on the modem or the DAA.