Cross-Platform Access

This section covers accessing PC and Macintosh-formatted MO disks on the Amiga, and also using an MO drive and disks with Macintosh and PC emulators on the Amiga.

Macintosh

It is very easy to use an MO drive and disks with emulators. I will only talk about the ShapeShifter Macintosh emulator here. Information on the Fusion and A-Max Mac emulators can be added if I am sent a (legal!) copy of these programs to test, or someone else contributes information.

There are two ways to use MO disks under Mac emulation:

You can use an MO disk as a "DeviceDisk". This is probably the quickest method. There are two disadvantages. Firstly, MO disks used like this will not be readable on a real Macintosh. Even if you buy a Mac-formatted MO disk, you will need to reformat it in order to use as a DeviceDisk. Secondly, ShapeShifter and Fusion do not currently support DeviceDisks with a sector size other than 512 bytes. This means that 640MB 3½" disks cannot be used as DeviceDisks, since they have 2048-byte sectors.
You can use Macintosh MO driver software. It is a good idea to buy an MO drive that comes bundled with Mac driver software. However, if your drive did not come with any you can download several free Mac SCSI driver packages. I recommend the Pinnacle Micro software.
My Philips Galaxy MO 640 drive came with Mac software called FormatterOne Pro, which can also be used to access many other types of SCSI device. FormatterOne Pro is a commercial product; see the Software Architects web site at: http://www.softarch.com/
In fact, the free Pinnacle Micro software seems to have more features than FormatterOne Pro. It allows disks to be low-level formatted, something which some Amiga SCSI tools can not do. However, the Pinnacle software is apparently incompatible with System 8. I also had some problems running it under System 7.0.1, though these may be partly due to my old SCSI controller or bugs in ShapeShifter.
If you use this or other Mac driver software, you can buy Mac-formatted MO disks and use them immediately under the Mac emulation. There are other commercial Mac drivers, though I have not used them. CharisMac sell "Anubis Pro", which you can buy as a competitive upgrade for US$14.95. Presumably you could download the free Pinnacle Micro software and then upgrade to Anubis Pro. For more information, see CharisMac's web page at: http://www.charismac.com/anubis.html
Some other Mac commercial driver products are Silverlining, Disk Drive TuneUp, FWB Hard Disk Toolkit and MicroNet DiskWorks.
Note that to use MO drives under ShapeShifter, the device type may need to be set to "direct access" because ShapeShifter's SCSI routines or some old SCSI drivers are buggy. See the Drive Settings section for information.

Accessing Macintosh disks from the Amiga for both reading and writing may require the commercial products CrossMac or MaxDOS. However, read-only access is possible by using filesystems such as AmiCDFileSystem or AmiCDFS which support Mac HFS CD-ROMs and floppies. If you have created multiple partitions on a Mac-formatted MO disk, you will need to make a mount file corresponding to each partition that you want to access.

There is an example mount file using AmiCDFS that works for my 640MB Mac-formatted MO disk. I used the Pinnacle Micro Mac driver software to format it as a real Mac volume, not a DeviceDisk. I created a single HFS partition on it, which occupies sectors 96 to 310349 inclusive (sectors 310350 & 310351 do not seem to be used). So the LowCyl and HighCyl values for the mountlist are 96 and 310349 respectively (using BlocksPerTrack = 1). If I were to use different Mac MO driver software, the LowCyl and HighCyl values would need to be altered appropriately.

When creating mount files for your Mac volumes, you need some way of finding which range of sectors the volume uses. If you are using a (512-byte sectors) MO disk as a DeviceDisk with an emulator, this should be no problem; LowCyl = 0 and HighCyl = (number of sectors in disk - 1) should work. Using a real Mac-formatted disk, you need to use a Mac utility program which tells you which sectors are used by each partition to get this information.

PC driver software is available from many manufacturers' web sites. The Fujitsu, Maxoptix, Philips and Pinnacle Micro sites are good places to start; see the Where to Get More Information section for their URLs. The Philips site has drivers for MS-DOS, Windows 3.1, Windows 95 & 98, Windows NT versions 3.51 and 4.0, and OS/2.

It is possible to mount PC-formatted (AT-HD type) MO disks as Amiga devices, just like PC0: is used to access PC-formatted floppy disks. This requires CrossDOS (supplied with Workbench 2.1 and higher) or similar. It is probably not possible to format this type of disk without special software, so format disks on a PC first. Accessing PC disks which have been formatted to contain several partitions is easy using CrossDOS. CrossDOS can be configured to automatically recognise and mount partitions on a disk; it determines where on the disk the partitions are by reading the partition table. See the MOC DOSDriver in the Example Mount Files section. Alternatively you could create a mount file for each partition. This has the disadvantage of being tied to a specific partition layout. It may be possible to use MountDOS to help with this.

On a PC, it is also possible to format MO disks in "superfloppy" format. This is probably similar to using a mount file as opposed to RDB for Amiga-formatted disks. Accessing such disks on the Amiga just requires a suitable mount file.

See the Example Mount Files section if you want to experiment with reading PC or Macintosh-formatted MO disks.

You should also investigate XFS which is a kind of "universal filesystem" that can access PC and Mac volumes. It supports Windows 95 long filenames, which is otherwise only possible with CrossDOS 7.0. The author of XFS has created a web page about it, which can be found at: http://www.xfilesystem.freeserve.co.uk/