Annotation of uae/docs/FAQ, revision 1.1.1.3

1.1       root        1: Some Frequently Asked Questions. Please read this carefully if you have
                      2: problems.
                      3: 
1.1.1.3 ! root        4: ** COMMON PROBLEMS
1.1.1.2   root        5: 
1.1.1.3 ! root        6: Q: Sometimes, after UAE exits, there is no autorepeat for the keys!
        !             7: A: Do "xset r on" (happens only in X, apparently mainly on Solaris boxes.
        !             8:    Dunno why.). [Should be fixed by now. Note that this always happens when
        !             9:    UAE crashes]
1.1.1.2   root       10: 
1.1.1.3 ! root       11: Q: When UAE starts up, it says "Illegal instruction: 4e7b". Why?
        !            12: A: That's normal, it's just the Kickstart CPU type test.
1.1.1.2   root       13: 
1.1.1.3 ! root       14: Q: When UAE starts up, it says "Illegal instruction: 00f8" (many times). Why?
        !            15: A: That's because your Kickstart ROM was compiled for the 68020.
        !            16:    (could also happen when there's a bug in UAE)
        !            17: 
        !            18: Q: When UAE loads <insert your favourite game> it says "Non-standard sync".
        !            19: A: Your favourite game is copy-protected. There are ways to transfer such
        !            20:    disks, but it's complicated and I won't help you because it would be much
        !            21:    too time-consuming to figure out all sorts of copy-protection schemes.
        !            22:    I hope there will be a general solution some day, but for now you're
        !            23:    unlucky.
        !            24: 
        !            25: Q: While it compiles, it says "xxx illegals generated" or "16 mismatches".
        !            26:    Is this a problem?
        !            27: A: No. I can use this information to tell whether there is a problem, and
        !            28:    there isn't.
        !            29: 
        !            30: Q: How can I produce an @ symbol (or any other sign)? On my PC keyboard it's 
        !            31:    AltGr+Q, but that doesn't seem to work.
        !            32: A: Look at the keyboard of your Amiga. Use the same combination that you would
        !            33:    need on a real Amiga. These combinations differ across countries. Make sure
        !            34:    you have loaded the right keyboard translation table for AmigaOS (e.g. in
        !            35:    Germany, make sure there's a "setmap de" command in the startup-sequence)
        !            36:    You can probably create a @ sign by pressing Alt+2, or Shift+2.
        !            37: 
        !            38: 
        !            39: ** INCOMPATIBILITIES
        !            40: 
        !            41: Q: UAE does not work with my Kickstart 1.2 image.
        !            42: A: You may need to turn off the harddisk and fastmem emulation with the "-a"
        !            43:    parameter. Kick 1.2 doesn't support the autoboot features that the harddisk
        !            44:    emulation requires.
        !            45:    You can tell that you are suffering from this problem if UAE gives you the
        !            46:    message "filesys_bput called".
        !            47: 
        !            48: Q: What do I do if a game/demo/application doesn't work?
        !            49: A: If you're trying to run a game or a demo, enable some slow RAM, and try
        !            50:    running it again.  Some older software has compatability problems which 
        !            51:    slow RAM can sometimes fix.  If it's an application, check for obvious
        !            52:    things like Kickstart version requirements, RAM, etc.  Also make sure the
        !            53:    software you're trying to run isn't for AGA equipped machines.
        !            54: 
        !            55: 
        !            56: ** AMIGA DISKS, DISK IMAGES, HARDDISKS, CDROMS
1.1       root       57: 
                     58: Q: Is it possible to read Amiga disks with a PC?
                     59: A: Ask that in comp.emulators.misc :-) The answer is: NO! Unless you invent
                     60:    and build some extra hardware yourself, which no one appears to have done
1.1.1.2   root       61:    yet. You'd also need some extra software driver; the whole setup would be
                     62:    similar to the X1541 cable/software for C64 emulators.
1.1.1.3 ! root       63:    Some people have pointed out that you can buy a controller named "Catweasl"
        !            64:    which apparently can read all sorts of disks on a PC, including Amiga
        !            65:    disks. Please don't ask for details, I don't have the thing and I can't
        !            66:    tell whether it works.
1.1       root       67: 
                     68: Q: Couldn't I attach an Amiga floppy drive to the PC somehow, and use that to 
                     69:    read Amiga disks?
                     70: A: You can attach Amiga (low-density) drives to the PC, because they are
                     71:    completely identical to PC drives. This won't help you, because the problem
                     72:    is not the drive, but the PC floppy controller. You have to live with it.
                     73: 
1.1.1.3 ! root       74: Q: But the PC can read 11-sector formats!
        !            75: A: Yes, but those sectors look a little different to the hardware.
        !            76: 
        !            77: Q: But the Amiga can read PC disks!
        !            78: A: So what?
        !            79: 
        !            80: Q: But the PC can read Atari ST disks!
        !            81: A: So what?
        !            82: 
1.1       root       83: Q: But...
1.1.1.3 ! root       84: A: No way. If you still are convinced that it must be possible, prove it. 
        !            85:    Write a program to read Amiga disks with a standard PC controller, and I
        !            86:    will apologize in public.
        !            87: 
        !            88: Q: How can I use DMS images?
        !            89: A: Run DMS under UAE and use it just like you would on a real Amiga.
        !            90:    Decompressing a DMS file to DF0: will overwrite the .adf file that is
        !            91:    currently used to emulate df0:.
1.1       root       92: 
1.1.1.2   root       93: Q: How can I transfer non-DOS disks that are used by many demos?
                     94: A: With transdisk. The fact that they are unreadable by AmigaDOS does not
                     95:    mean they are unreadble by transdisk. 
                     96:    Long explanation: There are two things to consider when talking about the
                     97:    "format" of a disk. First, the low-level format which divides each track
                     98:    into sectors in a special way. Most Amiga disks are in the standard Amiga
                     99:    format which has 11 sectors with 512 bytes each per track, with a total of 
                    100:    880K per disk. There's also some extra information outside the sectors so
                    101:    that the floppy controller can find the sectors. PC disks use a different 
                    102:    format, which is the reason why a PC controller can't read Amiga disks.
                    103:    If a disk is formatted this way, it can be copied with the normal AmigaDOS
                    104:    diskcopy program or the Workbench equivalent, and transdisk can handle it.
                    105:    Copy-protected disks have a different track layout (sometimes, they don't
                    106:    divide the tracks into sectors at all, or use more sectors, or put
                    107:    different things between the sectors. This type of thing can't be handled
                    108:    by diskcopy or by transdisk.
                    109:    Now, the second part of the "format" of a disk is the filesystem. If you
                    110:    want to put files and directories on a disk, you have to write some special
                    111:    information into some of the sectors on the disk. That information includes
                    112:    (for example) the name of the disk (e.g. "Workbench1.3"), and what files it
                    113:    contains. This information is called a "filesystem". The Amiga knows about
                    114:    several filesystems: There is the original filesystem (called OFS), and the
                    115:    newer Fast Filesystem (FFS) which was introduced with Kickstart 1.3.
                    116:    If you don't put a filesystem on the disk, the data in the sectors can still
                    117:    be read by programs like transdisk or diskcopy, but the data makes no sense
                    118:    to them. The point is, it doesn't have to. It only has to make sense for
                    119:    the Workbench which tries to determine what files there are on a disk. If
                    120:    the Workbench can't find a filesystem it knows about on the disk, it will
1.1.1.3 ! root      121:    be marked as a non-DOS disk (as opposed to an "unreadable" disk which you
        !           122:    get if the low-level format is different from the standard).
1.1       root      123: 
                    124: Q: How can I change diskfiles?
1.1.1.2   root      125: A: Your version of UAE may have a user interface (the X11 version does) which
                    126:    enables you to do this. Read your system-specific README file for details.
1.1.1.3 ! root      127:    You can also use the "uaectrl" programs from the "amiga" subdirectory.
1.1       root      128: 
1.1.1.3 ! root      129: Q: Why is the floppy emulation so slow, after all the disk image is on a
        !           130:    harddisk?
        !           131: A: Because the disk rotation is emulated. This is necessary. Use the harddisk
        !           132:    emulation wherever possible.
        !           133: 
        !           134: Q: <insert your favourite problem with the hardfile emulation here>
        !           135: A: Don't use the hardfile. Use the filesystem emulation ("-m" option).
        !           136: 
        !           137: Q: How can I read Amiga CD-ROMs?
        !           138: A: With the harddisk emulation. Give UAE the parameter "-M CD:/cdrom" if you
        !           139:    are using a Linux system with the CD mounted at /cdrom, or "-m CD:D:\" if
        !           140:    you are using DOS and D: is your CD-ROM drive (and if you have a different
        !           141:    system you should be able to figure out what to do)
1.1       root      142: 
                    143: Q: Is it possible to read Amiga harddisks with a PC?
                    144: A: Yes. Linux 2.0 has an Amiga filesystem that can reportedly read Amiga
1.1.1.2   root      145:    OFS/FFS harddisks. Please don't ask for details, I didn't write the thing,
1.1.1.3 ! root      146:    and I don't use it (yet). I did use it to read .adf disk images, though.
1.1       root      147: 
                    148: 
1.1.1.3 ! root      149: ** FUTURE PLANS
1.1       root      150: 
1.1.1.3 ! root      151: Q: When will the next version come out, and what will be in it?
        !           152: A: It will come out when it's done.
1.1       root      153: 
1.1.1.3 ! root      154: Q: Will there be a shareware version or some registration fee for future
        !           155:    versions of UAE?
        !           156: A: No.
1.1       root      157: 
1.1.1.3 ! root      158: Q: Couldn't you use ARDI's CPU emulation to speed it up?
        !           159: A: UAE is free software. It comes with sourcecode. ARDI's Executor is
        !           160:    proprietary and sold commercially. ARDI has no reason at all to give away
        !           161:    their code for free, because they wouldn't make any more money if they did.
        !           162:    (yes, I really get asked this kind of thing! I don't know where people take
        !           163:    these ideas from).
1.1       root      164: 
                    165: 
1.1.1.3 ! root      166: ** UAE SPEED
1.1       root      167: 
1.1.1.3 ! root      168: Q: I don't get steady sound output! I only have a 486DX40, could this be
        !           169:    related?
        !           170: A: Try a Pentium-II-300, these things are reported to do better.
1.1       root      171: 
                    172: Q: Would it be possible to speed it up by emulating the CPU native on, say,
                    173:    a 68k Mac?
                    174: A: I doubt it. UAE needs to be able to interrupt the CPU emulation anytime to
1.1.1.2   root      175:    perform tasks necessary for emulating the hardware. So you can't just let
                    176:    it run all by itself.
1.1       root      177: 
                    178: Q: Would it be possible to speed it up by using graphics accelerator boards
                    179:    for example by using the blitter in S3 chips?
1.1.1.2   root      180: A: I doubt it. I'm no PC graphics card expert, but probably the only thing the
                    181:    S3 blitter and the Amiga blitter have in common are seven lowercase
                    182:    letters. Even if they were similar you'd have to keep all Amiga chip
1.1       root      183:    RAM in the graphics memory and that would most likely make everything
                    184:    painfully slow.
                    185: 
1.1.1.3 ! root      186: Q: How about adding special support for the GUS/other wavetable boards that 
        !           187:    uses hardware features to speed up the sound emulation?
1.1.1.2   root      188: A: Again, due to the differences in Amiga and PC (in this case: GUS) hardware,
                    189:    this isn't really feasible. You _might_ get something like this to work in
                    190:    some special cases (ProTracker modules might be a case that could be made
                    191:    to work), but I don't think you can come up with something that emulates
                    192:    all of the Amiga sound hardware.
                    193:    The problem is that by just examining the values a program writes into the
                    194:    audio hardware registers, you can hardly figure out what a program is
                    195:    trying to do, and what it is going to do in the future. In contrast to
                    196:    that, it's easy to write a SoundTracker module player for GUS cards because
                    197:    you know exactly what you are playing, and how you have to do it.
                    198:    (That doesn't mean you can't use the GUS for sound output; you just can't
                    199:    use it to _speed up_ the sound output)
1.1       root      200: 
                    201: Q: Emulating all the hardware is a bad idea. Why don't you just emulate the
                    202:    OS? After all, that's what makes the Amiga the Amiga.
                    203: A: Short answer: I disagree. 
                    204:    Long answer: The OS is half of what makes the Amiga the Amiga. It is a very
                    205:    nice OS, and there are some features that I miss in any other OS, but it is
                    206:    also severely lacking in terms of (for example) memory protection and
                    207:    filesystem performance. 
                    208:    The other thing that made the Amiga special back in the 1980s is the custom 
                    209:    chip architecture. If you look into old (1985) computer magazines, you will 
                    210:    find that the capabilites of the Amiga OS are only mentioned as a side
                    211:    note, because people were not aware that it was revolutionary for a home 
                    212:    computer. They were aware, though, that the Amiga could display 4096 colors 
                    213:    at the same time and that it had a blitter and a copper that could do all
                    214:    sorts of stuff, like bouncing balls for instance. And I think it was the
                    215:    superiority of the hardware that made the Amiga a success.
                    216:    I see UAE as a program that is similar to C64 emulators: it allows you to
                    217:    run some old games and other programs that you can't replace with better
                    218:    equivalents on the PC. As such, it can already be used to run non-action
                    219:    games (like Monkey Island or Bard's Tale) at a satisfactory speed. Faster
                    220:    CPUs will eventually make it possible to run action games, just like faster
                    221:    CPUs have made it possible to emulate a C64 at full speed on a PC. UAE is 
                    222:    not (primarily) meant for the Amiga PowerUser who is running high quality
                    223:    applications on his A4000 with a 68060 board, but for people like me who
                    224:    switched from an A500 to the PC a few years ago because they wanted to make
                    225:    money by developing software.
                    226:    Besides, emulating an OS is far more difficult IMHO. Especially if the
                    227:    platform you are emulating it on is completely different than the platform
                    228:    that is being emulated. You'd have to mess with endianness conversions and
                    229:    other nightmares. The AmigaOS wasn't designed with portability in mind 
                    230:    either.
                    231: 
1.1.1.2   root      232: Q: How fast is it?
1.1.1.3 ! root      233: A: It depends.
        !           234:    For crunching files with PowerPacker, UAE is 17 times faster than my A500
        !           235:    on my K6-233.
        !           236:    For playing Turrican I, it's running at about full speed (with sound).
        !           237:    For playing Turrican III, it is slightly slower than the A500.
        !           238:    For some (not many) demos, it's a fair bit slower than the A500.
        !           239:    Rule of thumb: Sound emulation really takes time; so do copper effects and
        !           240:    scrolling. If you don't need either, you're fine.
1.1.1.2   root      241: 
                    242: Q: How can I make it faster?
                    243: A: Run the emulator in the lowest screen mode (320x200), set it to 256 colors,
                    244:    make sure aspect correction is disabled, and set the frame rate to every 3rd
                    245:    frame.  Finally, disable sound (if you have a version that lets you compile
                    246:    your own executable, set "DONT_WANT_SOUND" in config.h). It won't look very
                    247:    nice, but it will run as fast as your machine allows.
1.1.1.3 ! root      248:    If you are running the X version, make sure you use the "-T" option. Not
        !           249:    using this option is "safer", but makes the emulator very slow. Even better,
        !           250:    when you run configure, say "configure --enable-dga" if your X server
        !           251:    (XFree86 3.2 or higher) supports it.
        !           252:    It's especially important that you don't use 24 bit or 32 bit color modes.
1.1.1.2   root      253: 
1.1.1.3 ! root      254: 
        !           255: ** MISCELLANEOUS
        !           256: 
        !           257: Q: Do I need a real Amiga to use this program?
        !           258: A: Yes, unless you have some other way of legally getting ROM files and system
        !           259:    software, such as the Cloanto Amiga Forever CD.
        !           260: 
        !           261: Q: Where can I download a Kickstart ROM/Amiga games?
        !           262: A: Read the docs again. You can't. It would be illegal to put a ROM image or
        !           263:    other copyrighted software on the net (yes, even if you once bought a
        !           264:    specific Amiga game and sold it together with the computer, downloading the
        !           265:    same game now would still be illegal. Sorry.)
        !           266: 
        !           267: Q: Does UAE run on the DEC Alpha/Sparcstations/SGIs/whatever?
        !           268: A: UAE should run on all Unix systems that have at least X11R5 and a decent
        !           269:    C compiler installed. So the answer is probably yes. Just use the generic
        !           270:    Unix source and follow the instructions in README.UNIX to compile it.
        !           271: 
        !           272: Q: Why is there a blank area on the left side of the screen?
        !           273: A: The Amiga can display graphics there, but usually doesn't because this
        !           274:    would disable some sprites. The area is only used by some overscan demos.
        !           275:    Normal screens are off-center. I'm not going to do anything about that.
        !           276:    If you can't stand it, you can try to use 320x200 or 640x480 resolution,
        !           277:    which will attempt to center the screen. This is near impossible to get
        !           278:    right for every program. If your screen doesn't fit in lower resolutions,
        !           279:    use 800x600.
        !           280: 
        !           281: Q: Where is a complete summary of all command line switches ?
        !           282: A: In the README files. You can also generate it yourself by typing:
        !           283:    uae -h > uae-help.txt
        !           284: 
        !           285: Q: Benchmark program <insert your favourite benchmark> gives weird results.
        !           286: A: Amiga programs run by the emulator think the Amiga timers can be used to
        !           287:    measure real time. But in UAE, they only measure "emulation time". Sysinfo,
        !           288:    for example, gives the same results on all machines. So don't run
        !           289:    benchmarks to test the emulator speed.
        !           290:    Some benchmarks also use tight loops of DIV or MUL instructions to measure
        !           291:    CPU speed, and in "emulation time" these instructions take as much time
        !           292:    as any other instructions, and you'll get much too high values.
        !           293:    If you enabled the "HAVE_RDTSC" option, running benchmarks makes some more
        !           294:    sense. Still not a lot, since there is a minimum speed that the benchmark
        !           295:    will report on every machine. The faster the machine, the more accurate
        !           296:    will your results be.
        !           297: 
        !           298: Q: Wasn't this called the Unusable Amiga Emulator?
        !           299: A: Yes. But no one thought the name was very fitting anymore, though. It was
        !           300:    only really appropriate for v0.1, which couldn't even boot.

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