DR DOS 9.0 Change Log
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9.0 rev 265 - 2026-02-28
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  * Implement LIM EMS 4.0 (INT 67h) with XMS backend
  * Add BATCH.COM batch file processor
  * Add AUTOEXEC.BAT support on first boot
  * Add batch commands: ECHO, CD/CHDIR, DEL/ERASE, COPY, REN/RENAME, MKDIR/MD, RD/RMDIR
  * Add batch features: SHIFT, SET, CALL, %VAR% expansion, IF ERRORLEVEL
  * Add wildcard support for DEL command
  * Add IF EXIST support for device names (NUL, CON)
  * Implement INT 21h AH=67h JFT expansion
  * Properly implement . and .. directory entries
  * Set archive bit automatically on file creation and modification
  * Increase minimum system requirements to 386
  * Fix CHS disk I/O reliability
  * Fix AH=69h crash by using bounce buffer for CHS disk read compatibility
  * Fix INT 21h AH=6Ch extended open action flags and register handling
  * Fix FAT cache stale data bug for multi-cluster files
  * Fix 16-bit overflow in FAT entry write for clusters >= 0x8000
  * Fix multi-cluster directory support in EXEC, rename, MKDIR, and file lookup
  * Fix AUX device I/O (INT 21h AH=03h/04h) incorrectly routing to printer

9.0 rev 205 - 2026-02-21
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  * Add full-screen text editor (EDIT.COM)
  * Add PS/2 mouse driver (MOUSE.COM) with INT 33h API support
  * Add pipe support and output redirection (cmd | MORE, cmd > file)
  * Add MORE, DIR, JMP, PEEK, & POKE programs
  * Implement JFT/SFT file handle architecture
  * Implement INT 21h AH=04h,05h,0Dh,11h,12h,1Bh,1Ch,23h,24h,26h,2Dh,2Eh,34h,3Ah,45h,46h,54h,55h,57h,58h,59h,60h,63h,66h,67h,68h,69h,6Ch
  * Add extended key (scan code) support to console input functions
  * CHS fallback for systems without LBA support
  * Report DOS version 6.0 for compatibility
  * Fix day of week calculation in INT 21h AH=2Ah
  * Fix FAT entry lookup overflow for large volumes (clusters >= 0x8000)
  * Fix COM/EXE program exit via RET instruction
  * Fix FCB functions to search current directory instead of root
  * Fix EXEC to correctly calculate EXE load size from MZ header
  * Fix IOCTL file handle mapping and AH=43h attribute return

9.0 rev 126 - 2026-02-14
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  * Improved XMS memory allocation
  * Improved support for DOS extenders
  * Increased available conventional memory / Load kernel into HMA
  * Improved MEM output & behavior
  * Fixed "CD .." to correctly return to the parent directory
  * Implement INT 2Fh AX=4A01h
  * Support for second fixed disks (D: drive support)


9.0 rev 107 - 2026-02-07
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  * Implement INT 15h AH=88h
  * Implement INT 21h AH=03h,28h,4Bh,50h,51h, & 52h
  * Fix stack imabalance bug in EXEC
  * Expose CON & NUL devices in SYSVARS
  * Add CLS, MEM, HEXDUMP, & DATE programs
  * Improved conventional memory availability
  * Support for nested folders
  * Support for larger volumns beyond single sector FAT
  * Fix program ENV to be a proper copy & include program name
  * Support for reading larger files
  * Improved file I/O performance


9.0 rev 86 - 2026-01-31
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  * Initial public release