Annotation of uae/docs/FAQ, revision 1.1.1.4

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.
1.1.1.4 ! root       54:    You can also try changing various other options, like the CPU type. For
        !            55:    games, sometimes "-C0c" will make it work.
1.1.1.3   root       56: 
                     57: 
                     58: ** AMIGA DISKS, DISK IMAGES, HARDDISKS, CDROMS
1.1       root       59: 
                     60: Q: Is it possible to read Amiga disks with a PC?
1.1.1.4 ! root       61: A: No, and yes. No, with a standard PC it's impossible. However, with some
        !            62:    additional hardware (i.e. a new floppy controller) it is possible. I
        !            63:    currently know of two solutions, the AFR package which consists of a small
        !            64:    parallel port interface that you have to build yourself and some software,
        !            65:    and the Catweasel controller which is available as an ISA card and comes
        !            66:    with DOS software that can create disk files. I have a Catweasel here, and
        !            67:    it does in fact work.
1.1       root       68: 
                     69: Q: Couldn't I attach an Amiga floppy drive to the PC somehow, and use that to 
                     70:    read Amiga disks?
                     71: A: You can attach Amiga (low-density) drives to the PC, because they are
                     72:    completely identical to PC drives. This won't help you, because the problem
                     73:    is not the drive, but the PC floppy controller. You have to live with it.
                     74: 
1.1.1.3   root       75: Q: But the PC can read 11-sector formats!
                     76: A: Yes, but those sectors look a little different to the hardware.
                     77: 
                     78: Q: But the Amiga can read PC disks!
                     79: A: So what?
                     80: 
                     81: Q: But the PC can read Atari ST disks!
                     82: A: So what?
                     83: 
1.1       root       84: Q: But...
1.1.1.3   root       85: A: No way. If you still are convinced that it must be possible, prove it. 
                     86:    Write a program to read Amiga disks with a standard PC controller, and I
                     87:    will apologize in public.
                     88: 
                     89: Q: How can I use DMS images?
                     90: A: Run DMS under UAE and use it just like you would on a real Amiga.
                     91:    Decompressing a DMS file to DF0: will overwrite the .adf file that is
                     92:    currently used to emulate df0:.
1.1       root       93: 
1.1.1.2   root       94: Q: How can I transfer non-DOS disks that are used by many demos?
                     95: A: With transdisk. The fact that they are unreadable by AmigaDOS does not
                     96:    mean they are unreadble by transdisk. 
                     97:    Long explanation: There are two things to consider when talking about the
                     98:    "format" of a disk. First, the low-level format which divides each track
                     99:    into sectors in a special way. Most Amiga disks are in the standard Amiga
                    100:    format which has 11 sectors with 512 bytes each per track, with a total of 
                    101:    880K per disk. There's also some extra information outside the sectors so
                    102:    that the floppy controller can find the sectors. PC disks use a different 
                    103:    format, which is the reason why a PC controller can't read Amiga disks.
                    104:    If a disk is formatted this way, it can be copied with the normal AmigaDOS
                    105:    diskcopy program or the Workbench equivalent, and transdisk can handle it.
                    106:    Copy-protected disks have a different track layout (sometimes, they don't
                    107:    divide the tracks into sectors at all, or use more sectors, or put
                    108:    different things between the sectors. This type of thing can't be handled
                    109:    by diskcopy or by transdisk.
                    110:    Now, the second part of the "format" of a disk is the filesystem. If you
                    111:    want to put files and directories on a disk, you have to write some special
                    112:    information into some of the sectors on the disk. That information includes
                    113:    (for example) the name of the disk (e.g. "Workbench1.3"), and what files it
                    114:    contains. This information is called a "filesystem". The Amiga knows about
                    115:    several filesystems: There is the original filesystem (called OFS), and the
                    116:    newer Fast Filesystem (FFS) which was introduced with Kickstart 1.3.
                    117:    If you don't put a filesystem on the disk, the data in the sectors can still
                    118:    be read by programs like transdisk or diskcopy, but the data makes no sense
                    119:    to them. The point is, it doesn't have to. It only has to make sense for
                    120:    the Workbench which tries to determine what files there are on a disk. If
                    121:    the Workbench can't find a filesystem it knows about on the disk, it will
1.1.1.3   root      122:    be marked as a non-DOS disk (as opposed to an "unreadable" disk which you
                    123:    get if the low-level format is different from the standard).
1.1       root      124: 
                    125: Q: How can I change diskfiles?
1.1.1.2   root      126: A: Your version of UAE may have a user interface (the X11 version does) which
                    127:    enables you to do this. Read your system-specific README file for details.
1.1.1.3   root      128:    You can also use the "uaectrl" programs from the "amiga" subdirectory.
1.1       root      129: 
1.1.1.3   root      130: Q: Why is the floppy emulation so slow, after all the disk image is on a
                    131:    harddisk?
                    132: A: Because the disk rotation is emulated. This is necessary. Use the harddisk
                    133:    emulation wherever possible.
                    134: 
                    135: Q: <insert your favourite problem with the hardfile emulation here>
                    136: A: Don't use the hardfile. Use the filesystem emulation ("-m" option).
                    137: 
                    138: Q: How can I read Amiga CD-ROMs?
                    139: A: With the harddisk emulation. Give UAE the parameter "-M CD:/cdrom" if you
                    140:    are using a Linux system with the CD mounted at /cdrom, or "-m CD:D:\" if
                    141:    you are using DOS and D: is your CD-ROM drive (and if you have a different
                    142:    system you should be able to figure out what to do)
1.1       root      143: 
                    144: Q: Is it possible to read Amiga harddisks with a PC?
                    145: A: Yes. Linux 2.0 has an Amiga filesystem that can reportedly read Amiga
1.1.1.2   root      146:    OFS/FFS harddisks. Please don't ask for details, I didn't write the thing,
1.1.1.3   root      147:    and I don't use it (yet). I did use it to read .adf disk images, though.
1.1       root      148: 
                    149: 
1.1.1.3   root      150: ** FUTURE PLANS
1.1       root      151: 
1.1.1.3   root      152: Q: When will the next version come out, and what will be in it?
                    153: A: It will come out when it's done.
1.1       root      154: 
1.1.1.3   root      155: Q: Will there be a shareware version or some registration fee for future
                    156:    versions of UAE?
                    157: A: No.
1.1       root      158: 
1.1.1.3   root      159: Q: Couldn't you use ARDI's CPU emulation to speed it up?
                    160: A: UAE is free software. It comes with sourcecode. ARDI's Executor is
                    161:    proprietary and sold commercially. ARDI has no reason at all to give away
                    162:    their code for free, because they wouldn't make any more money if they did.
                    163:    (yes, I really get asked this kind of thing! I don't know where people take
                    164:    these ideas from).
1.1       root      165: 
                    166: 
1.1.1.3   root      167: ** UAE SPEED
1.1       root      168: 
1.1.1.3   root      169: Q: I don't get steady sound output! I only have a 486DX40, could this be
                    170:    related?
                    171: A: Try a Pentium-II-300, these things are reported to do better.
1.1       root      172: 
                    173: Q: Would it be possible to speed it up by emulating the CPU native on, say,
                    174:    a 68k Mac?
                    175: A: I doubt it. UAE needs to be able to interrupt the CPU emulation anytime to
1.1.1.2   root      176:    perform tasks necessary for emulating the hardware. So you can't just let
                    177:    it run all by itself.
1.1       root      178: 
                    179: Q: Would it be possible to speed it up by using graphics accelerator boards
                    180:    for example by using the blitter in S3 chips?
1.1.1.2   root      181: A: I doubt it. I'm no PC graphics card expert, but probably the only thing the
                    182:    S3 blitter and the Amiga blitter have in common are seven lowercase
                    183:    letters. Even if they were similar you'd have to keep all Amiga chip
1.1       root      184:    RAM in the graphics memory and that would most likely make everything
                    185:    painfully slow.
                    186: 
1.1.1.3   root      187: Q: How about adding special support for the GUS/other wavetable boards that 
                    188:    uses hardware features to speed up the sound emulation?
1.1.1.2   root      189: A: Again, due to the differences in Amiga and PC (in this case: GUS) hardware,
                    190:    this isn't really feasible. You _might_ get something like this to work in
                    191:    some special cases (ProTracker modules might be a case that could be made
                    192:    to work), but I don't think you can come up with something that emulates
                    193:    all of the Amiga sound hardware.
                    194:    The problem is that by just examining the values a program writes into the
                    195:    audio hardware registers, you can hardly figure out what a program is
                    196:    trying to do, and what it is going to do in the future. In contrast to
                    197:    that, it's easy to write a SoundTracker module player for GUS cards because
                    198:    you know exactly what you are playing, and how you have to do it.
                    199:    (That doesn't mean you can't use the GUS for sound output; you just can't
                    200:    use it to _speed up_ the sound output)
1.1       root      201: 
                    202: Q: Emulating all the hardware is a bad idea. Why don't you just emulate the
                    203:    OS? After all, that's what makes the Amiga the Amiga.
                    204: A: Short answer: I disagree. 
                    205:    Long answer: The OS is half of what makes the Amiga the Amiga. It is a very
                    206:    nice OS, and there are some features that I miss in any other OS, but it is
                    207:    also severely lacking in terms of (for example) memory protection and
                    208:    filesystem performance. 
                    209:    The other thing that made the Amiga special back in the 1980s is the custom 
                    210:    chip architecture. If you look into old (1985) computer magazines, you will 
                    211:    find that the capabilites of the Amiga OS are only mentioned as a side
                    212:    note, because people were not aware that it was revolutionary for a home 
                    213:    computer. They were aware, though, that the Amiga could display 4096 colors 
                    214:    at the same time and that it had a blitter and a copper that could do all
                    215:    sorts of stuff, like bouncing balls for instance. And I think it was the
                    216:    superiority of the hardware that made the Amiga a success.
                    217:    I see UAE as a program that is similar to C64 emulators: it allows you to
                    218:    run some old games and other programs that you can't replace with better
                    219:    equivalents on the PC. As such, it can already be used to run non-action
                    220:    games (like Monkey Island or Bard's Tale) at a satisfactory speed. Faster
                    221:    CPUs will eventually make it possible to run action games, just like faster
                    222:    CPUs have made it possible to emulate a C64 at full speed on a PC. UAE is 
                    223:    not (primarily) meant for the Amiga PowerUser who is running high quality
                    224:    applications on his A4000 with a 68060 board, but for people like me who
                    225:    switched from an A500 to the PC a few years ago because they wanted to make
                    226:    money by developing software.
                    227:    Besides, emulating an OS is far more difficult IMHO. Especially if the
                    228:    platform you are emulating it on is completely different than the platform
                    229:    that is being emulated. You'd have to mess with endianness conversions and
                    230:    other nightmares. The AmigaOS wasn't designed with portability in mind 
                    231:    either.
                    232: 
1.1.1.2   root      233: Q: How fast is it?
1.1.1.3   root      234: A: It depends.
                    235:    For crunching files with PowerPacker, UAE is 17 times faster than my A500
                    236:    on my K6-233.
                    237:    For playing Turrican I, it's running at about full speed (with sound).
                    238:    For playing Turrican III, it is slightly slower than the A500.
                    239:    For some (not many) demos, it's a fair bit slower than the A500.
                    240:    Rule of thumb: Sound emulation really takes time; so do copper effects and
                    241:    scrolling. If you don't need either, you're fine.
1.1.1.2   root      242: 
                    243: Q: How can I make it faster?
                    244: A: Run the emulator in the lowest screen mode (320x200), set it to 256 colors,
                    245:    make sure aspect correction is disabled, and set the frame rate to every 3rd
                    246:    frame.  Finally, disable sound (if you have a version that lets you compile
                    247:    your own executable, set "DONT_WANT_SOUND" in config.h). It won't look very
                    248:    nice, but it will run as fast as your machine allows.
1.1.1.3   root      249:    If you are running the X version, make sure you use the "-T" option. Not
                    250:    using this option is "safer", but makes the emulator very slow. Even better,
                    251:    when you run configure, say "configure --enable-dga" if your X server
                    252:    (XFree86 3.2 or higher) supports it.
                    253:    It's especially important that you don't use 24 bit or 32 bit color modes.
1.1.1.2   root      254: 
1.1.1.3   root      255: 
                    256: ** MISCELLANEOUS
                    257: 
                    258: Q: Do I need a real Amiga to use this program?
                    259: A: Yes, unless you have some other way of legally getting ROM files and system
                    260:    software, such as the Cloanto Amiga Forever CD.
                    261: 
                    262: Q: Where can I download a Kickstart ROM/Amiga games?
                    263: A: Read the docs again. You can't. It would be illegal to put a ROM image or
                    264:    other copyrighted software on the net (yes, even if you once bought a
                    265:    specific Amiga game and sold it together with the computer, downloading the
                    266:    same game now would still be illegal. Sorry.)
                    267: 
                    268: Q: Does UAE run on the DEC Alpha/Sparcstations/SGIs/whatever?
                    269: A: UAE should run on all Unix systems that have at least X11R5 and a decent
                    270:    C compiler installed. So the answer is probably yes. Just use the generic
                    271:    Unix source and follow the instructions in README.UNIX to compile it.
1.1.1.4 ! root      272:    However, using GCC and the GNU binutils can improve your chances.
1.1.1.3   root      273: 
                    274: Q: Why is there a blank area on the left side of the screen?
                    275: A: The Amiga can display graphics there, but usually doesn't because this
                    276:    would disable some sprites. The area is only used by some overscan demos.
                    277:    Normal screens are off-center. I'm not going to do anything about that.
                    278:    If you can't stand it, you can try to use 320x200 or 640x480 resolution,
                    279:    which will attempt to center the screen. This is near impossible to get
                    280:    right for every program. If your screen doesn't fit in lower resolutions,
                    281:    use 800x600.
                    282: 
                    283: Q: Where is a complete summary of all command line switches ?
                    284: A: In the README files. You can also generate it yourself by typing:
                    285:    uae -h > uae-help.txt
                    286: 
                    287: Q: Benchmark program <insert your favourite benchmark> gives weird results.
                    288: A: Amiga programs run by the emulator think the Amiga timers can be used to
                    289:    measure real time. But in UAE, they only measure "emulation time". Sysinfo,
                    290:    for example, gives the same results on all machines. So don't run
                    291:    benchmarks to test the emulator speed.
                    292:    Some benchmarks also use tight loops of DIV or MUL instructions to measure
                    293:    CPU speed, and in "emulation time" these instructions take as much time
                    294:    as any other instructions, and you'll get much too high values.
                    295:    If you enabled the "HAVE_RDTSC" option, running benchmarks makes some more
                    296:    sense. Still not a lot, since there is a minimum speed that the benchmark
                    297:    will report on every machine. The faster the machine, the more accurate
                    298:    will your results be.
                    299: 
                    300: Q: Wasn't this called the Unusable Amiga Emulator?
                    301: A: Yes. But no one thought the name was very fitting anymore, though. It was
                    302:    only really appropriate for v0.1, which couldn't even boot.

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