The LaserWriter 8500 external SCSI port is designed to be compatible with many of the under-2GB SCSI hard drives currently available. Unfortunately, Apple does not have the resources to test and certify all of the hundreds of hard drives models that customers might have access to. When purchasing an external font hard drive make sure that it is less than 2GB in size. If possible, test the hard drive to make sure it is compatible before purchasing it.
To format the hard drive the following steps should be performed once:
1. Connect the hard drive to the printer using the appropriate cables and terminator.
2. Power on the hard drive and the LaserWriter 8500.
3. With the printer networked to at least one Macintosh, launch the Apple Printer Utility version 2.2 or newer.
4. Select the LaserWriter 8500 from the printer list and then press the 'Open Printer' button.
5. Open the 'Disks' category and select the hard drive to be initialized.
6. Wait several minutes for the initialization process to be completed.
Attempting to install hard drives larger than 2GB may cause the printer report an error when formatting or in some cases, to alternately flash the paper out and paper jam LEDs indicating hardware failure. In all cases, disconnecting the external hard drive and restarting the printer should clear the reset error.
The following hard drive mechanisms appear to format and store fonts without any problems. This list is not comprehensive so other hard drives should also work fine.
| Brand | Model | Size |
| Quantum | ProDrive LPS | 250MB |
| Seagate | ST-11200N SCSI-2 Fast (Hawk 1) | 1GB |
| Seagate | ST-12550N SCSI-2 Fast (Barracuda 2) | 2GB |