CD Rom
A simple guide to CD-ROM drive emulation for Diablo II Classic and Lord of Destruction.
This scheme will make the disc checks that are done in various acts proceed much faster than normal, as your hard drive is about as fast as a 1500x drive which never has a spin-up or spin-down lag time. Access speeds are far faster, and data caches can improve on that as well. Also, you reduce a great deal of wear and tear on your optical drives by emulating them, and remove the threat of losing gameplay time and playability entirely by being able to archive your original discs in a secure location.
Out of all the various 3rd party programs available that COULD be used with D2 ... I believe that cd-rom drive emulation, ATMA V single player muling program/drop calculator, and Foxbat's D2 Accellerator are the only ones permitted for legit play.
Windows
First... Download Alcohol 52% (trial version = free)and Daemon Tools (freeware/shareware).
Next, burn the ISO image of Diablo II: Lord of Destruction with Securom 4.3 copy protection emulation enabled (this creates an ISO disc image and a Media Descriptor File .mds) to your Hard Drive.
Then place the created ISO and MDS files in a final destination directory which you will not delete or move or rename. Mount the MDS file using Daemon Tools cd-rom emulator (NOT THE ISO). This will point Daemon Tools to the ISO for you, and emulate cd copy protection. Remember to keep the MDS and ISO files together at all times, and dont move them from their final directory. If the path is broken, you will have to go back and re-mount the drive using the MDS from it's new location every time.
Macintosh
MacOS X users who own Roxio Toast can use it to emulate a CDROM drive for Diablo II.
Simply rip the playdisc (Diablo II Playdisc or Diablo II: Lord of Destruction) as a Toast-format image file. Then, use Toast's "Mount Image File" feature to mount the image. Diablo II should start normally.
It maybe be possible to do the same thing using Disk Utility (instead of the commercial Toast) but I have not verified that.
MacOS Classic users can use Toast or Disk Copy to rip and mount an image file of the playdisc. Diablo II patches 1.07 and earlier will play normally. 1.08 and up will not accept this, and will require a physical CD in a physical drive.
Note that the Macintosh side of the playdisc can be copied using Toast without any special copy protection worries, so you can at least play using a backup playdisc. This has saved my bacon several times over!