I'm writing a DOS utility (primarily targeting MS-DOS 5.0-7.0) which uses int 25h/26h to modify a FAT16 partition, including the FATs and root directory entries. Ideally I'd like to be able to use this partition immediately afterwards without rebooting. There won't be any open files from this drive at the time, but I'm worried about DOS caching sectors (in particular, the FAT itself) and not realizing I've rewritten them. Is this a significant concern, or does int 26h ensure cache consistency? If it is a concern, how can I tell DOS to invalidate its cache?
Recent Questions - Retrocomputing Stack Exchange · Aug 17, 2026
Absolute disk read/write interrupts and sector caching
0Sign in to vote or save
This page did not load. You can still read it on the original site — the toolbar below keeps your place in the directory.
I'm writing a DOS utility (primarily targeting MS-DOS 5.0-7.0) which uses int 25h/26h to modify a FAT16 partition, including the FATs and root directory entries. Ideally I'd like to be able to use this partition immediately afterwards without rebooting. There won't be any open files from this drive at the time, but I'm worried about DOS caching sectors (in particular, the FAT itself) and not…
Comments
Nothing yet. Say the first thing.
Sign in to join the conversation.