Security lock ports are used to physically lock desktop Macintosh computers to a desk or other stationary object using some kind of cable locking system.
Apple uses four different types of security lock ports on Macintosh computers. They are as follows:
| PORT TYPE | DESCRIPTION |
| Large rectangular port | The original security port is a rectangular port that measures approximately 6mm x 35mm at the opening. |
| Small rectangular port | A slightly smaller rectangular port that measures approximately 6mm x 22mm at the opening. |
| 1/4" Mini-slot port | A 3mm x 7mm opening without latches of any kind. It uses a different type of security device than the previous security lock ports. |
| Cable Slotted port | A plastic loop on the bottom of the unit that is intended to have a security cable fed through it. |
Use the following chart to determine which type of security device you need for your Macintosh computer.
Note: Generally, security lock ports are located on the back panels of most Macintosh computers or, in the case of the cable slotted port, on bottom panels.
| Compact Macintosh |
| Macintosh 128K | Large rectangular port | Right center |
| Macintosh 512K, 512Ke | Large rectangular port | Right center |
| Macintosh Plus | Large rectangular port | Right center |
| Macintosh SE | Small rectangular port | Center |
| Macintosh SE/30 | Small rectangular port | Center |
| Macintosh Classic | Small rectangular port | Left center |
| Macintosh Classic II | Small rectangular port | Left center |
| Macintosh Color Classic | Small rectangular port | Center |
| Macintosh II |
| Macintosh II | Small rectangular port | Lower right corner |
| Macintosh IIx | Small rectangular port | Lower right corner |
| Macintosh IIcx | Small rectangular port | Next to Nubus slots |
| Macintosh IIci | Small rectangular port | Next to Nubus slots |
| Macintosh IIfx | Small rectangular port | Lower right corner |
| Macintosh IIsi | Small rectangular port | Lower left corner |
| Macintosh IIvx | Small rectangular port | Next to Nubus slots |
| Macintosh IIvi | Small rectangular port | Next to Nubus slots |
| Macintosh LC Series |
| Macintosh LC | Cable Slotted port | Bottom right corner |
| Macintosh LC II | Cable Slotted port | Bottom right corner |
| Macintosh LC III | Cable Slotted port | Bottom right corner |
| Macintosh LC 475 | Cable Slotted port | Bottom right corner |
| Macintosh LC 520 | Small rectangular port | Center |
| Macintosh LC 550 | Small rectangular port | Center |
| Macintosh LC 575 | Small rectangular port | Center |
| Macintosh TV | Small rectangular port | Center |
| Macintosh LC 580 | Small rectangular port | Center |
| Macintosh LC 5200 | Cable slotted port | Center |
| Performa Series |
| Performa 200 |
| Performa 400, 405, 430, 450 | Cable Slotted port | Bottom right corner |
| Performa 475 & 476 | Cable Slotted port | Bottom right corner |
| Performa 550 | Small rectangular port | Center |
| Performa 575 | Small rectangular port | Center |
| Performa 577 | Small rectangular port | Center |
| Performa 578 | Small rectangular port | Center |
| Performa 600 | Small rectangular port | Next to Nubus slots |
| Quadra and Centris Series |
| Quadra 605 | Cable Slotted port | Bottom right corner |
| Quadra/Centris 610 | 1/4" Mini-Slot | Next to AC receptacle |
| Macintosh 630 family | 1/4" Mini-Slot | Next to AC receptacle |
| Quadra/Centris 650 | Small rectangular port | Next to Nubus slots |
| Quadra/Centris 660AV | 1/4" Mini-Slot | Next to AC receptacle |
| Quadra 700 | Small rectangular port | Next to NuBus slots |
| Quadra 800 | Small rectangular port | Lower right corner |
| 1/4" Mini-Slot | Lower right corner |
| Quadra 840AV | Small rectangular port | Lower right corner |
| 1/4" Mini-Slot | Lower right corner |
| Quadra 900 | Small rectangular port | Lower left corner |
| Quadra 950 | Small rectangular port | Lower left corner |
| Power Macintosh |
| Power Macintosh 6100 | 1/4" Mini-Slot | Next to AC receptacle |
| Power Macintosh 7100 | 1/4" Mini-Slot | Next to Nubus slots |
| Power Macintosh 8100 | Small rectangular port | Lower right rear |
| 1/4" Mini-Slot | Lower right rear |
| Power Macintosh 9500 | Small rectangular port | Lower right rear |
| 1/4" Mini-Slot | Lower right rear |
| Apple Workgroup Servers |
| Workgroup Server 60 | 1/4" Mini-Slot | Next to AC receptacle |
| Workgroup Server 80 | Small rectangular port | Lower right corner |
| Workgroup Server 95 | Small rectangular port | Lower left corner |
| Workgroup Server 6150 | 1/4" Mini-Slot | Next to AC receptacle |
| Workgroup Server 8150 | Small rectangular port | Lower right corner |
| 1/4" Mini-Slot | Lower right corner |
| Workgroup Server 9150 | Small rectangular port | Lower left corner |