The Mezzanine Slot
A personal computer interface { not to be confused with PCI } slot present in the first two revisions of the iMac, a self-contained Apple computer. It was axed with the advent of the "fruit flavored" iMacs, having been deemed "unsupported" by Apple { it was originally intended for testing purposes }, and thereafter leaving the iMac with nothing in the way of expansion options. On the earlier Bondi blue models, its presence is denoted by a white slot with "MEZZANINE" printed to the side of it. In later models, the connectors are still intact but the slot is not. While an option was once available from a now defunct vendor to restore the functionality, Apple warned that this would void the warranty of the computer.
Options for expansion were few, due to the nature of the slot. Among them are a now antiquated video card featuring the Voodoo 2 chipset { boasting 8mb of memory } and an UltraWide SCSI interface card. Installing these components can be tricky, as the slot is located on the reverse side of the motherboard. In its time of glory, veteran users still tended to opt for installation by a professional.