📅 2026-01-15
· ✍️ Bas v.d. Wiel
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🏷
update
Supporting DOS 3.xx turns out to be something of a challenge due to a lack of authoritative documentation. There simply is no documentation that describes, accurately, how different versions of DOS lay out hard disk structures for the many different types of hardware available at the time. This is a problem for a project that aims for accuracy. So FATFudge was born.
FATFudge is turning into a developer tool that mass-generates hard disk images and runs actual historical DOS versions to partition and format them. This leans heavily on third-party tools like Qemu to emulate a 386 PC, SQLite for database management and some Rust glue to pull relevant metadata from the generated disk images.
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📅 2025-08-13
· ✍️ Bas v.d. Wiel
·
🏷
announcement
The roadmap to DOSContainer v3.00 is an ambitious one for a project that’s only maintained by a
single person in part-time. A number of features is on the cooker right now, which will take quite
a lot of time before completion. Here they are in some more detail.
Support PC-DOS 3.00
PC-DOS 3.00 is just another version of the IBM-branch of DOS. Supporting that, in and of itself, is
not that much of a problem. It’s a matter of adding boot sector binaries, system files, and to make
branches in the code where data structures get serialized into OS-specific on-disk bytes. The most work
goes into figuring out whether or not those on-disk bytes are different at all, for which IBM’s docs
are not the most reliable source.
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📅 2025-07-23
· ✍️ Bas v.d. Wiel
·
🏷
announcement
The previous releases were made silently and source-only because the turbulent state of flux the project
is still in. This time I’m making an official announcement: version 2.00 just finished building and is
ready for use. This version covers IBM PC-DOS 1.00, 1.10 and 2.00 on floppies and hard disk images suitable
for their time period. This version is ideal if you want to create disk images for the original IBM 5150
or XT with the proper disk geometries and OS system files in the right place.
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📅 2025-06-22
· ✍️ Bas v.d. Wiel
·
🏷
documentation
This is something of a journal entry. I’m preparing to start work on implementing PC-DOS 2.00 compatibility,
which means creating a bunch of pristine floppy and hard disk images to base my implementation on. 86Box is
my friend here, as is the ghex utility for looking at every single byte. While trawling through a disk image,
sometime I discover something intriguing. Apparently, PC-DOS 2.00 injects a bunch of stuff into the area of
the disk where the FAT’s live but these bytes have nothing at all to do with the FAT’s. In fact, should the
disk get enough files and subdirectories, these bytes would get mercilessly clobbered by the growing FAT. So,
what gives?
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DOSContainer