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<TITLE>File access</TITLE> |
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<BODY> |
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<H1>File access</H1> |
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<HR> |
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Frodo offers four possibilities for the 1541 emulation: |
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<H3>1. Host system directory, setting "Dir"</H3> |
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In this mode, the C64 programs and files are stored in a directory on your |
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hard disk and can be <KBD>LOAD</KBD>ed and <KBD>SAVE</KBD>d as usual from |
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the emulator. The paths to the directories of the simulated drives are |
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given in the settings window in the path entry fields of the "Drives" |
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box.<P> |
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You can also load the directory with <KBD>LOAD"$",8</KBD>. All files are |
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displayed as "PRG", all subdirectories as "DIR". To get into a |
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subdirectory, you have to open the settings window and change the path for |
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the drive, as the operating system of the C64 doesn't know about |
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subdirectories. However, it is possible to use a "/" in the C64 file name |
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to access these subdirectories (e.g. <KBD>LOAD"GAMES/ELITE",8</KBD>), |
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unless the '/' translation setting is turned on.<P> |
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For the opening of files, the file types "P" and "S" and the access modes |
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"R", "W" and "A" are supported. Wildcards (*,?) can be used, but you have |
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to remember that files in BeOS/Unix/AmigaOS directories have no determined order |
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and the result of <KBD>LOAD"*",8</KBD> is rather random. Files are always |
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overwritten even if they are not opened with "@:". Floppy commands other |
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than "I" and "UJ", relative files and direct block access are not |
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implemented. You can however read the error channel.<P> |
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<H3>2. .d64/x64 disk image file, setting "D64"</H3> |
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Most C64 programs available on the Internet and on CD-ROMs, expecially |
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demos and games, are stored in files with the ending ".d64". Such a file |
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holds all 683 blocks of a complete side of a 1541 disk, so that direct |
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block accesses are possible from within the emulation. However, Frodo only |
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supports read accesses. The path name of the disk image file must be given |
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in the settings window in the path entry fields of the "Drives" box.<P> |
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Apart from .d64 files, Frodo can also use image files of the "x64" |
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emulator, automatically detecting the file type.<P> |
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<H3>3. .t64/LYNX archive file, setting "T64"</H3> |
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.t64 and LYNX (.lnx) files are archive files like "tar". .t64 files are |
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also often found on the Internet and on CD-ROMs; LYNX is a native C64 |
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archiver. Frodo's .t64 support is a bit special in that it doesn't treat |
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the .t64 file like a tape image (that's what the .t64 format was designed |
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for), but rather like a disk image file. .t64's are not accessed with |
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device number 1 (Frodo doesn't have any tape emulation), but with numbers |
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8..11 like a disk drive.<P> |
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When loading the directory with <KBD>LOAD"$",8</KBD>, Frodo creates a |
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listing of all files within the archive. You cannot write to .t64 or LYNX |
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files, they are read-only under Frodo.<P> |
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<H3>4. Processor-level 1541 emulation</H3> |
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The 1541 is an "intelligent" disk drive bearing its own CPU and memory that |
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can even be programmed and execute code concurrently to the C64. Frodo is |
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able to emulate a 1541 on this level, but as this slows down the whole |
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emulation notably, the 1541 processor emulation can be turned on and off |
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from the settings.<P> |
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If the 1541 processor emulation is turned on, the "Dir"/"D64" drives 8..11 |
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are no longer available. They are replaced by a single drive with number 8 |
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that operates in "D64" mode (regardless of the state of the type setting |
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for drive 8). The path name of the .d64/x64 file to be used must be given |
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in the path entry field of drive 8.<P> |
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In contrast to the standard "D64" mode, the 1541 processor emulation is |
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able to write to the disk. There is no way to "virtually write-protect" the |
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disk image file, so be careful. |
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