adamd@rhi.hi.is (Adam David) (05/08/91)
These are the new fd devices 2,16 and 2,17 for variable media parameters. I've just hacked format together to handle higher capacity floppies. During the verify stage it is necessary to open the relevant rfd device instead of rsd or rdd because the disk may have more sectors or tracks than the usual ones. To handle HD media correctly without major redesigning it is necessary to reformat all of track 00 with a boot sector instead of just writing the boot sector. I tried opening /dev/rfd0 to a disk in drive 0 but the open always fails no matter what format the disk has (I've also tried working disks). The changes to stfloppy.c only affect the /dev/fmt?d? devices and are as follows: '#define MAX_CYLS 84' used to initialise nr_cyls during format operations. Introduction of global variables instead of some #define-d constants to allow for High-Density media (1680 kB) during format, also let /dev/fmtfd? refer to HD formatting. So, why is it that /dev/rfd? fails during open()? (I didn't break it). Has anybody already tackled the issue of formatting different floppy disk parameters under minix? There are several issues involved, most notably which interleave and skew factors to use and reducing the inter-sector gap to add another 10% to disk capacity. -- Adam David. (adamd@rhi.hi.is)