Expects: AX 4404H (INT 21H IOCTL Read service number)
BL any compressed drive number (1=A, 2=B, etc)
CX 10 (size of an DsIoctlRec; see below)
DS:DX address of a DsIoctlRec with an 'F' (ASCII 46H) in
Info: DoubleSpace maintains internal caches for its cluster data,
This IOCTL fn forces DoubleSpace to update the CVF on disk to
reflect the currently-cached data.
The cache is still considered valid. Use DS IOCTL 'I' to force
DoubleSpace to invalidate the cache and re-read the disk.
DS:DX points to a DsIoctlRec as follows:
+0 2 abSig must be 444dH ('M','D')
+2 1 bCmdCode must be 46H ('F') Flush command
10 size of a DsIoctlRec structure
To use this fn, set up the packet and the registers, and call
INT 21H. See DOS fn 44H (device I/O Control) for related DOS
On return, check bResult for an error code. The value 4f4bH
('OK') indicates success.
Note: You can force DoubleSpace and SmartDrive to flush their disk-
sector caches via DOS fn 0dH (reset disk).