Amiga Emulation Disks

When it comes to using emulated hard drives in FS-UAE, you have several choices: • You can mount directories on your system as Amiga volumes (“directory hard drives”). • You can use hard drive images (HDF files). • You can mount zip files as Amiga volumes. • You can in some cases use a real Amiga hard drive / compact flash card. The best choice depends on how you want to use it. The most convenient is directory hard drives, and I recommend to use this unless you have a good reason not to, especially with FS-UAE v2.1.28+, when support for file permission and metadata was added.

Amiga systems/games are PAL (50Hz), but modern TVs typically default to a 60Hz mode when connected to a Raspberry Pi. Enter the RunCommand menu for your Amiga emulator, and select a valid mode that uses a 50Hz refresh rate in order to match the original PAL rate, and thus, eliminate stuttering. These emulated Amiga software programs consist of demos and music disks from 20 years of community coding. A thank you to the Scripted Amiga Emulator project, as well.

Using Directory Hard Drives The advantages of using directory hard drives compared with other approaches are: • It will work with all Amiga models, with no Amiga-side setup needed. The volumes (directories) will automatically be accessible from the Amiga.

• You’ll have “unlimited” Amiga storage capacity (as long as you have enough free space on your system), and you don’t have to allocate space upfront as you must do with HDFs. • You can also access the files directly from the host system, and you can easily add new files to your Amiga drive from the host system. Note: you should be somewhat careful about modifying the directory hard drive from the Amiga and from the host system at the same time. Ideally, you should only modify the hard drive from the host system when FS-UAE is not running, since some information about the file system may be cached in the Amiga. Amiga and Host File Names Some file names which are valid on the Amiga are not allowed on the host file system. This is particularly true on Windows, which has one of the most restrictive set of allowed file names (Linux and OS X are more flexible). FS-UAE handles this by “escaping” the invalid Amiga file names so the can be stored on the local file system.

This is only done when necessary, so most file names will not be escaped. Also, the escaping is done so the host file name is valid on all supported FS-UAE platforms. For example, the following file name is valid on the amiga: Foo Bar This is not valid on Windows however, so the file name is escaped and stored as Foo%5cBar. The Amiga will see a file called Foo Bar when it accesses a directory with a host file called Foo%5cBar.

Since Foo Bar is not allowed on Windows, the file is stored as Foo%5cBar on *all* platforms. This makes the directory hard drives portable across multiple operating systems. See also “Extracting Amiga Archives” for more relevant information. Amiga File Permissions The information in this section applies to FS-UAE v2.1.28+. Earlier versions do not store file permissions.

When FS-UAE looks up existing files in a directory hard drives, it initializes metadata about the file either from the host file system, or if it exists, from an accompanying metadata file. When a file has an accompanying metadata file, date/time, file permissions and comment are read from the metadata file. If a metadata file does not exist, then: • The file will get the default permissions: ----rwed. • The file date/time will be read from the last modified timestamp of the host file. • The file will have no file comment.

When files are created/modified from within the Amiga, the host file mtime (last modified time) is updated based on the Amiga file date/time. FS-UAE then decides if it needs to store more information about the file in a metadata file: • If the file has a file comment, FS-UAE will create a metadata file. • If the file has non-default file permissions, FS-UAE will create a metadata file. • FS-UAE reads back the last modified time from the host file, and checks that the time was stored with high enough precision (Amiga files are stored with 1/50s precision). If the time could not be stored accurately, FS-UAE will create a metadata file.

• If the file already has a metadata file, FS-UAE will always update the metadata file. Additional metadata is stored in files with.uaem extension. If the original file is called Image.jpg, the additional metadata is stored in Image.jpg.uaem in the same directory. The metadata is stored in a text format, and you can even edit this file manually from the host side to alter the information about the file.

Here’s an example of the content of a metadata file (where “hello” is a file comment): ----rwed 2013-02-12 21:20:52.02 hello Note: file permissions / comments are not stored with FS-UAE. I’m having trouble setting up AmigaOS 4.1 on my iMac with FS-UAE v2.8.3. Serial Do Sonar Le 8.5 more.