[LisaFAQ] > [Hardware]

3.7.1. How do I low level format my ProFile hard drive?

When installing an operating environment, such as the Lisa Office System or one of the MacWorks variants, all of the sectors of a ProFile/Widget hard disk are written with zeros before the actual file system structures are written to the disk.

If this initialization fails consistently, it is possible that the drive is damaged and needs low-level formatting and/or further repair.

A low-level format is different from the normal initialization that installing an operating system on a ProFile or Widget does. During low level formatting, extra synchronization markers and track/sector ID's are written on the tracks in between the sector gaps to help the hard drive find the sector/track it's seeking.

In normal operation, this extra data is never written to. Over time, the strength of the magnetic signal of this data can fade, or is physically damaged as vibrations cause the r/w heads to smash into the platter.

When this happens, you get data errors. In cases where the damage is limited to only a few sectors, the hard drive can relocate a damaged sector to one of the spare sectors. ProFile drives have up to 32 spare sectors. Once they run out, any more damage results in symptoms such as loss of data and instability to the OS.

Should the first track be damaged, the OS will not be able to install and use the drive.

If using the OS installer to re-initialize/format the drive fails, the first level of service to address these issues is to do a low-level format. Unfortunately, in order to do this, you'll need an Apple /// computer with a ProFile interface card, the special low-level format ROM for the ProFile's Z8 processor, and the Apple /// ProFile formatting software to issue the commands. ProFile hard drives configured for normal operation do not have the firmware necessary to do low-level formats.

The technique, hardware, and software required to perform a low-level format of a Widget hard drive is unknown.

Low-level formatting cannot cure all problems, as damage to the disk surface or electronic failures may require replacement of some components. In short, for most of us, low-level formatting is just not possible. You're better off buying a replacement hard drive.

If someone out there has the right hardware to perform low-level formatting, please let us know if you'd be willing to perform this valuable service for the Lisa community.

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