ARCHIVED: How do I low-level format an MFM or RLL drive?
A low-level format actually does a physical format; it lays down tracks and sectors. It is the first format for a hard disk, and is used later to extend the life of an old drive to refresh the media. It wipes all information, just like reformatting a floppy disk.
Doing a regular format on a hard drive merely re-organizes the File Allocation Table (FAT), and doesn't really erase the disk or lay down tracks and sectors.
Spinrite, mentioned below, actually reads information off the disk, and re-writes it as it finishes formatting sectors on the disk, which is why it is not destructive like an ordinary low-level format. The instructions below work for small-disk Western Digital and Adaptec MFM and RLL controllers. Newer controllers usually use bundled software for low-level formatting.
WARNING: DO NOT LOW-LEVEL FORMAT IDE DRIVES!
It is best to do this from a bootable floppy. The floppy should have DEBUG.COM, FDISK.COM and FORMAT.COM on it.
The old 10MB IBM XT drives have to be low-level formatted using a routine on the IBM Advanced Diagnostics diskette. Zenith machines use the PREP command in Zenith DOS. Other older machines require use of the debug utility.
At the A:\> prompt, type:
debug
You will get a "-" prompt. At this point, type:
G=C800:5 -or- for Western Digital controllers G=C800:800
G=C800:CCC for Adaptec controllers.
G=C800:5 for DTC (Data Technonolgy) controllers
G=C800:6 for OMTI controllers
Spinrite is a good alternative to ordinary low-level formatting, because it doesn't destroy the contents of a disk. However, it does not work with many kinds of drives, especially those that use sector translation.
This is document aaoa in the Knowledge Base.
Last modified on 2023-09-22 17:25:12.