walters@oksce1.okstate.edu (Harold G. Walters) (10/14/89)
In general need to know how to set the floppy disk type so that it can be read with the DOS interrupts 0x25 and 0x26. Some background. I wrote some routines that access the disk directly through interrupts 0x25 and 0x26 (these are the DOS direct read and write functions that bypass the logical structure of the disk). In order for these to work one must first place a DOS formatted disk of the density you want into the floppy drive and access it (by doing a dir or some such). This sets some parameters internal to DOS and DOS "remembers" what type/density the disk is. I can then change to another floppy with the same density and access it with my routines even though the new floppy's boot sector is not a boot sector anymore (it gets replaced with arbitrary data). I have seen floppy drivers under UN*X determine the density of floppy disk even though it has no boot sector so I know the hardware is there to do it. Even DOS has to do it somehow. What I would like is a way to access the disk from inside my program and have it set the DOS internals so that DOS would be able to read the floppy at the proper density through interrupts 0x25 and 0x26. The question is can it be done through DOS or BIOS routines. Any help is much appreciated. Harold G. Walters walters@1.ce.okstate.edu School of Civil Engineering okstate!oksce1!walters Oklahoma State University "If all you have is a hammer, Stillwater, OK 74078 everything looks like a nail". -- Harold G. Walters walters@1.ce.okstate.edu School of Civil Engineering okstate!oksce1!walters Oklahoma State University "If all you have is a hammer, Stillwater, OK 74078 everything looks like a nail".