/FHQ10: Why do the other windows slow to a virtual halt when one window
accesses the floppy disk?/FB



Both DOS and the BIOS disk access functions are non-reentrant, i.e. they
may not be called again while one call is in progress.  DESQview thus
handles both as ``serially reusable resources,'' and suspends a window
making such a call until any current call completes.



Since programs make many DOS calls other than disk I//O, they can become
blocked while another window is accessing the disk even when they
themselves are not trying to access the disk.  The same suspension
occurs when a program accesses the disk via BIOS calls, but only when
some other window is also accessing the disk; thus, a non-disk DOS call
can execute at the same time as a disk-related BIOS call.



When the disk being accessed is a hard disk, the call completes so
quickly that there is no obvious degradation in the performance of other
windows.  When accessing a floppy disk, however, the call can take
multiple seconds to complete, during which time it is highly likely that
other windows will be suspended for a noticeable length of time.



To minimize the impact of copying or formatting, try using shareware
programs such as DVCOPY, LTFORMAT and FDFORMAT /JB(see Q7)/q7.txt/.