The Orange Micro Grappler SCSI Serial card does not work properly with the new G4/733 Macs. Al Mateczun received this note from Orange Micro in response to his experience that the card caused a G4/733 to freeze on boot after the cursor appears, but before the happy Mac icon is displayed:
Reports of failure on the Apple Power Macintosh G4 (Digital Audio) 667 and 733 MHz models have been received. Orange Micro is looking into this issue. When a fix is available, it will be posted on the Software Updates page for Grappler SCSI products. The Grappler SCSI cards are compatible with pre digital audio G4 Power Macintosh systems. Based on recent end user feedback the new Apple Power Macintosh G4 (Digital Audio) computers 466 and 533 MHz models are also compatible.