On Thu, 9 Dec 2004, Michael Devore wrote: > Do FreeDOS disk accesses via INT 21h, INT 13h, INT whatever, read and write > directly from/to a passed address or do they always buffer the disk > access? Never? Sometimes?
Sometimes. > If never/sometimes, is there is a way to make it buffer always rather than > directly read/write to/from address. No. This would require source code changes. > If always/sometimes, is there a way to make it never buffer? No. This is impossible. Only whole sectors (in practise, 512-byte chunks at the right file-alignment) can be transferred without buffering. Anything else needs to go via the BUFFERS (as set in config.sys). The low level disk device driver also contains code that forces buffering if the segment of the address is >= 0xa000, using a different (internal to the device driver) buffer. So if you can force buffering in the int21-calling software by reading/writing <= 511 bytes or using an UMB or HMA transfer address but not globally. Bart ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/ _______________________________________________ Freedos-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/freedos-devel
