Operating systemsDOS (MS-DOS / DR-DOS) › MS-DOS 6.22

MS-DOS 6.22

1994

The 1994 final standalone MS-DOS, bundling DoubleSpace/DriveSpace disk compression, defragmentation and antivirus tools.

Machines

Chips

Reference & documentation

External technical references for programming MS-DOS and for writing PC/DOS emulators.

ResourceTypeNotes
Microsoft FAT File System Specification (fatgen103) ↗FormatOfficial Microsoft FAT12/16/32 filesystem spec
Microsoft FAT Specification ↗FormatPrimary Microsoft FAT spec v1.03 (PDF)
FAT Filesystem (OSDev Wiki) ↗FormatFAT12/16/32 layout, BPB, directory entries
DOS MZ executable format (Kaitai Struct) ↗FormatMZ EXE header, field-by-field binary spec
MZ .EXE Executable (OSDev Wiki) ↗FormatDOS .EXE header and relocation table
Ralf Brown's Interrupt List (HTML) ↗Interrupt list9000+ pages; every documented & undocumented INT
Ralf Brown's Interrupt List (master files) ↗Interrupt listAuthor's canonical release downloads
PC Memory Layout and Memory Map ↗Memory mapConventional, UMA, HMA address ranges tabulated
x86 Memory Map (OSDev Wiki) ↗Memory mapReal-mode conventional/upper memory, IVT, BDA
The Art of Assembly Language (DOS/16-bit edition) ↗ProgrammingClassic real-mode x86 assembly programming text
16-Bit DOS Programming (Irvine, Ch.13) ↗ProgrammingINT 21h/10h assembly tutorial (PDF)
WinWorldPC - MS-DOS 6.22 ↗ROMsInstall floppy / VHD images, all localisations
FreeDOS Project ↗ROMsOpen-source DOS: source, compilers, downloads
MS-DOS 6.22 Disk Images (Internet Archive) ↗ROMsBootable 1.44MB install floppy .img files
HelpPC: INT 21 DOS Function Dispatcher ↗ReferenceQuick INT 21h function-by-function lookup table
List of undocumented DOS functions ↗ReferenceUndocumented INT 21h calls and internal tables
MS-DOS Encyclopedia (Ray Duncan) ↗ReferenceBrowsable 1988 classic: calls, TSRs, interrupts
OS/2 Museum - DOS Internals ↗ReferenceDeep articles: A20, HMA, TSR, internals
Microsoft MS-DOS Source Code ↗SourceOfficial asm sources for v1.25, 2.0, 4.0