history.doc

History of device drivers:
1.00  Initial release
1.10  Added into IOCTL_msg media_change byte, that must be changed to
      -1 by srdisk if media changed. Changed header version to SRD 1.10.
1.20  Fixed name of program by adding the missing 'Re' to 'Sizeable'.
      Upgraded IOCTL_msg_s to version 1.20 by adding byte to tell usable
      memory types.
      Updated to work with DOS versions 2.x-5.x - not tested.
1.30
      Major redesign of the reformatting system. Ioctl is no longer used.
      New data structures of version V_FORMAT 0 (beta format).
      Support for multiplex interrupt.
      Support for chaining of drivers for different memory to same disk.
      Support for DOS 4+ 32-bit sector addresses.
      [Allow forcing drive to some drive letter (even replace DOS drives).]
      Int 19 hooking is optional by defining HOOKINT19 to 0.
      Added if ... endif around all memory specific code to ease
       later adding of other memory support code.
      Fixed parameter reading to abort on every ctrl-character other
       than tab. DOS 5 could end line with LF if no parameters and CR if
       there were parameters. Now even NUL can end the line.
1.40
      Moved the allocation conditionally out from this device driver.
       If C_NOALLOC in CAPABLE is set, the SRDISK.EXE is expected to do
       the allocation by itself.
      Changed multiplex interrupt interface to be more standardlike.
      Changed XMS handle to default 0 as indication there is no handle
       already allocated.
      Made the default BPB to contain a valid disk layout. The zero sectors
       in BPB made DR-DOS hang with divide error.
      Added check for DR-DOS 6 since it tells the init request header is
       not long enough to hold the drive letter, but the drive letter is
       there anyway.
1.42
      Split into three files: xmsdisk.asm, define.inc and this srdisk.asm
      Made it not to allocate a handle before one is needed.
      Removed drive forcing code - it had a bug since 1.40 and in any
       case made things only worse.
1.50
      Generic IOCTL support.
      disk_IO interface changed.
      Clarified code by writing dosstruc.inc and using the structures
1.51
      Made it read the BPB from the boot sector being written to the disk.