Memory models, FAT, interrupts, and the open-source continuation of the original PC OS.
On December 31, 2001, Microsoft stopped supporting and patching MS-DOS 6.22 and older versions — though DOS embedded within Windows 95/98/Me lingered in support for years afterward.
On June 29, 1994, a Usenet post to comp.os.msdos.apps proposing a public-domain DOS kicked off what would be renamed Free-DOS weeks later — a direct response to Microsoft's plans to fold MS-DOS into Windows 95.
Long filenames show up truncated to 8.3 format in some programs but not others, even with DOSLFN loaded. This is expected, driver-specific behavior — here's how to tell which programs actually support it.
FreeDOS boots with the wrong date or time every session, or DATE/TIME commands don't stick. Here's how to distinguish a dying CMOS battery from a software configuration issue.
FreeDOS reached its first stable 1.0 release on September 3, 2006 — twelve years after Jim Hall's original 1994 call to build a free DOS.
FreeDOS 1.3 shipped February 20, 2022, continuing the project's roughly five-year major release rhythm with an updated package set.
A practical tour of FreeDOS batch scripting: variables, control flow, argument handling, and the quirks that differ from a modern shell.
How a FreeDOS machine goes from the boot sector to a command prompt, and how CONFIG.SYS and AUTOEXEC.BAT configure everything along the way.
How character and block device drivers register with the DOS kernel through a standard request-header protocol, loaded declaratively from CONFIG.SYS.
How the File Allocation Table represents files as linked chains of clusters, and why that simple design has both strengths and hard limits.