Int 13 Fn 2C  u - Quickcache Ii V4.20 - Set Buffered Writes                [c]

   AH = 2Ch
   AL = new state (00h disabled, 01h enabled)

Return: AX = status (0000h successful)
Desc:  specify whether the cache should delay disk writes

Note:  this function enables or disables delayed writes for all drives; use
     AH=38h to change a single drive

See Also: AH=25h"QUICKCACHE",AH=2Dh,AH=2Eh,AH=38h