FreeDOSDeep Dive 5 min read
Upper Memory Blocks and Loading TSRs High
How DOS users reclaimed conventional memory by relocating drivers and TSRs into unused upper memory gaps, which varied by machine and BIOS.
#umb#tsr#memory-optimization
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FreeDOS posts
Memory models, FAT, interrupts, and the open-source continuation of the original PC OS.
FreeDOSDeep Dive 5 min read
XMS, EMS, and the Many Kinds of DOS Memory Beyond 640K
Why DOS ended up with three separate, incompatible ways to access memory beyond the conventional 640K barrier, and what each one was actually solving.
#xms#ems#memory-management
Read more FreeDOSFix 3 min read
Fixing DOSLFN Long Filename Problems on FreeDOS
Why long filenames appear truncated in some programs but not others even with DOSLFN loaded, and how to tell which behavior is actually expected.
#fix#doslfn#filenames
Read more FreeDOSFix 4 min read
Fixing Incorrect Date and Time on FreeDOS
How to distinguish a dying CMOS battery from a software configuration issue when FreeDOS boots with the wrong date or time every session.
#fix#rtc#date-time
Read more FreeDOSNews 5 min read
FreeDOS 1.0 Released, 12 Years After the Project Began
FreeDOS 1.0 arrived September 3, 2006 with installable base and full distributions, a boot floppy, package tools, source media, and a LiveCD option.
#news#release#freedos
Read more FreeDOSNews 5 min read
FreeDOS 1.3 Released
FreeDOS 1.3 arrived February 20, 2022 with kernel 2043, FreeCOM 0.85a, an 8086 FAT32 build, restored networking, compressed floppy media, and installer fixes.
#news#release#freedos
Read more FreeDOSDeep Dive 7 min read
Writing Batch Files on FreeDOS
A FreeCOM-specific guide to portable DOS batch files using arguments, SHIFT, IF, ERRORLEVEL, FOR, GOTO, CALL, redirection, and defensive expansion.
#batch-files#scripting#freedos
Read more FreeDOSDeep Dive 7 min read
The FreeDOS Boot Process: CONFIG.SYS and AUTOEXEC.BAT
A forensic walkthrough of FreeDOS startup from BIOS, MBR and volume boot code through KERNEL.SYS, FDCONFIG.SYS, FreeCOM, FDAUTO.BAT, drivers, and recovery keys.
#boot#config-sys#freedos
Read more FreeDOSDeep Dive 7 min read
Device Drivers on FreeDOS: How .SYS Files Extend the Kernel
A source-backed tour of FreeDOS device headers, character and block drivers, request packets, entry points, INIT, status words, and loading risks.
#device-drivers#kernel#freedos
Read more FreeDOSDeep Dive 7 min read
FAT12 and FAT16 Internals: The Filesystem Behind FreeDOS
A forensic guide to FreeDOS FAT12, FAT16 and FAT32 layout, cluster typing, directory and VFAT entries, allocation chains, mirrors, corruption, and recovery.
#fat#filesystem#freedos
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