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1.1 root 1: Some Frequently Asked Questions. Please read this carefully if you have
2: problems.
3:
1.1.1.2 ! root 4: Q: Where can I download a Kickstart ROM/Amiga games?
! 5: A: Read the docs again. You can't. It would be illegal to put a ROM image or
! 6: other copyrighted software on the net (yes, even if you once bought a
! 7: specific Amiga game and sold it together with the computer, downloading the
! 8: same game now would still be illegal. Sorry.)
! 9:
! 10: Q: When will version 1.0 come out, and what will be in it?
! 11: A: I have no idea. I don't give too much thought about the version numbers.
! 12: The only thing I can say about them is that they increase monotonically. I
! 13: also can't really say what features will be added. As many as useful, I
! 14: hope.
! 15:
! 16: Q: Will you support CyberGFX (or some other standard) to make the Workbench
! 17: run in a higher resolution?
! 18: Couldn't you use ARDI's CPU emulation to speed it up?
! 19: A: UAE is free software. It comes with sourcecode. ARDI's Executor, and as
! 20: far as I know all the Amiga graphics card "standards" are proprietary and
! 21: sold commercially. The companies that make these programs have no reason at
! 22: all to give away their code for free, because they wouldn't make any more
! 23: money if they did.
! 24: The only option for better graphics support is to rewrite the graphics
! 25: library with a native equivalent. That's a huge amount of work.
! 26: (yes, I really get asked this kind of thing! I don't know where people take
! 27: these ideas from).
! 28:
! 29: Q: Will there be any form of support for high-resolution graphics modes
! 30: (e.g. Workbench in 1024x768)?
! 31: A: I don't know yet. I hope so, but there are some technical difficulties.
! 32: There are several options how it might be implemented:
! 33: - reimplement all of the Amiga OS: Painful. No, it wouldn't suffice
! 34: just to rewrite graphics.library native as I once thought naively.
! 35: That wouldn't work. You'd need a native kernel (i.e. exec.library)
! 36: to get it to work because graphics and esp. intuition multitask
! 37: happily and that doesn't work in native emulation code yet.
! 38: (There are some bits and pieces in execlib.c, and it even occasionally
! 39: boots if you turn these on, so you may want to play with that if
! 40: you're a programmer)
! 41: - emulate graphics card hardware: _should_ be rather easy, once you get
! 42: chipset documentation (maybe steal from Linux/68k, I think they have
! 43: some support for graphics cards in their X server). You'd still need
! 44: some form of commercial support software, i.e. a CyberGFX or EGS driver
! 45: or whatever for the particular graphics card model that's emulated.
! 46:
! 47: Q: Does UAE run on the DEC Alpha/Sparcstations/SGIs/whatever?
! 48: A: UAE should run on all Unix systems that have at least X11R5 and a decent
! 49: C compiler installed. So the answer is probably yes. Just use the generic
! 50: Unix source and follow the instructions in README.UNIX to compile it.
1.1 root 51:
52: Q: Is it possible to read Amiga disks with a PC?
53: A: Ask that in comp.emulators.misc :-) The answer is: NO! Unless you invent
54: and build some extra hardware yourself, which no one appears to have done
1.1.1.2 ! root 55: yet. You'd also need some extra software driver; the whole setup would be
! 56: similar to the X1541 cable/software for C64 emulators.
1.1 root 57:
58: Q: Couldn't I attach an Amiga floppy drive to the PC somehow, and use that to
59: read Amiga disks?
60: A: You can attach Amiga (low-density) drives to the PC, because they are
61: completely identical to PC drives. This won't help you, because the problem
62: is not the drive, but the PC floppy controller. You have to live with it.
63:
64: Q: But...
65: A: No way.
66:
1.1.1.2 ! root 67: Q: How can I transfer non-DOS disks that are used by many demos?
! 68: A: With transdisk. The fact that they are unreadable by AmigaDOS does not
! 69: mean they are unreadble by transdisk.
! 70: Long explanation: There are two things to consider when talking about the
! 71: "format" of a disk. First, the low-level format which divides each track
! 72: into sectors in a special way. Most Amiga disks are in the standard Amiga
! 73: format which has 11 sectors with 512 bytes each per track, with a total of
! 74: 880K per disk. There's also some extra information outside the sectors so
! 75: that the floppy controller can find the sectors. PC disks use a different
! 76: format, which is the reason why a PC controller can't read Amiga disks.
! 77: If a disk is formatted this way, it can be copied with the normal AmigaDOS
! 78: diskcopy program or the Workbench equivalent, and transdisk can handle it.
! 79: Copy-protected disks have a different track layout (sometimes, they don't
! 80: divide the tracks into sectors at all, or use more sectors, or put
! 81: different things between the sectors. This type of thing can't be handled
! 82: by diskcopy or by transdisk.
! 83: Now, the second part of the "format" of a disk is the filesystem. If you
! 84: want to put files and directories on a disk, you have to write some special
! 85: information into some of the sectors on the disk. That information includes
! 86: (for example) the name of the disk (e.g. "Workbench1.3"), and what files it
! 87: contains. This information is called a "filesystem". The Amiga knows about
! 88: several filesystems: There is the original filesystem (called OFS), and the
! 89: newer Fast Filesystem (FFS) which was introduced with Kickstart 1.3.
! 90: If you don't put a filesystem on the disk, the data in the sectors can still
! 91: be read by programs like transdisk or diskcopy, but the data makes no sense
! 92: to them. The point is, it doesn't have to. It only has to make sense for
! 93: the Workbench which tries to determine what files there are on a disk. If
! 94: the Workbench can't find a filesystem it knows about on the disk, it will
! 95: be marked as a non-DOS disk.
1.1 root 96:
97: Q: How can I change diskfiles?
1.1.1.2 ! root 98: A: Your version of UAE may have a user interface (the X11 version does) which
! 99: enables you to do this. Read your system-specific README file for details.
! 100: You can also use the UAE_CONTROL programs from the "amiga" subdirectory.
! 101:
! 102: Q: UAE does not work with my Kickstart 1.2 image.
! 103: A: You may need to turn off the harddisk and fastmem emulation with the "-a"
! 104: parameter. Kick 1.2 doesn't support the autoboot features that the harddisk
! 105: emulation requires.
1.1 root 106:
107: Q: The "configure" script does not find Tcl/Tk, but I have it installed!
108: A: The script checks for an executable called "wish4.0". There is currently
109: no better test. Unfortunately, this executable is not always present,
110: even though Tk 4.0 is installed. If that is the case, find the "wish"
111: executable, go into the directory where you found it and type
112: "ln -s wish wish4.0" (provided you have write rights in that directory,
113: i.e. you are super-user). Then go back to the UAE directory, remove the
114: file config.cache and rerun "configure". That should do the trick.
115:
116: Q: Is it possible to read Amiga harddisks with a PC?
117: A: Yes. Linux 2.0 has an Amiga filesystem that can reportedly read Amiga
1.1.1.2 ! root 118: OFS/FFS harddisks. Please don't ask for details, I didn't write the thing,
! 119: and I don't use it (yet).
1.1 root 120:
121: Q: When UAE starts up, it says "Illegal instruction: 4e7b". Why?
122: A: That's normal, it's just the Kickstart CPU type test.
123:
124: Q: When UAE starts up, it says "Illegal instruction: 00f8" (many times). Why?
125: A: That's because your Kickstart ROM was compiled for the 68020.
1.1.1.2 ! root 126: (could also happen when there's a bug in UAE)
1.1 root 127:
128: Q: When UAE loads <insert your favourite game> it says "Non-standard sync".
129: A: Your favourite game is copy-protected. There are ways to transfer such
130: disks, but it's complicated and I won't help you because it would be much
131: too time-consuming to figure out all sorts of copy-protection schemes.
132: I hope there will be a general solution some day, but for now you're
133: unlucky.
134:
135: Q: While it compiles, it says "xxx illegals generated" or "16 mismatches".
136: Is this a problem?
137: A: No. I can use this information to tell whether there is a problem, and
138: there isn't.
139:
140: Q: Why is there a blank area on the left side of the screen?
141: A: The Amiga can display graphics there, but usually doesn't because this
142: would disable some sprites. The area is only used by some overscan demos.
143: Normal screens are off-center. I'm not going to do anything about that.
1.1.1.2 ! root 144: If you can't stand it, you can try to use 320x200 or 640x480 resolution,
! 145: which will attempt to center the screen. This is near impossible to get
! 146: right for every program. If your screen doesn't fit in lower resolutions,
! 147: use 800x600.
1.1 root 148:
149: Q: Benchmark program <insert your favourite benchmark> gives weird results.
150: A: Amiga programs run by the emulator think the Amiga timers can be used to
151: measure real time. But in UAE, they only measure "emulation time". Sysinfo,
152: for example, gives the same results on all machines. So don't run
153: benchmarks to test the emulator speed.
1.1.1.2 ! root 154: Some benchmarks also use tight loops of DIV or MUL instructions to measure
1.1 root 155: CPU speed, and in "emulation time" these instructions take as much time
156: as any other instructions, and you'll get much too high values.
157:
158: Q: Wasn't this called the Unusable Amiga Emulator?
159: A: Yes. But no one thought the name was very fitting anymore, though. It was
160: only really appropriate for v0.1, which couldn't even boot.
161:
162: Q: Sometimes, after UAE exits, there is no autorepeat for the keys!
163: A: Do "xset r on" (happens only in X, apparently mainly on Solaris boxes.
1.1.1.2 ! root 164: Dunno why.). [Should be fixed by now. Note that this always happens when
! 165: UAE crashes]
1.1 root 166:
167: Q: Would it be possible to speed it up by emulating the CPU native on, say,
168: a 68k Mac?
169: A: I doubt it. UAE needs to be able to interrupt the CPU emulation anytime to
1.1.1.2 ! root 170: perform tasks necessary for emulating the hardware. So you can't just let
! 171: it run all by itself.
1.1 root 172:
173: Q: Would it be possible to speed it up by using graphics accelerator boards
174: for example by using the blitter in S3 chips?
1.1.1.2 ! root 175: A: I doubt it. I'm no PC graphics card expert, but probably the only thing the
! 176: S3 blitter and the Amiga blitter have in common are seven lowercase
! 177: letters. Even if they were similar you'd have to keep all Amiga chip
1.1 root 178: RAM in the graphics memory and that would most likely make everything
179: painfully slow.
180:
1.1.1.2 ! root 181: Q: How about adding special support for the GUS that uses hardware features
! 182: to speed up the sound emulation?
! 183: A: Again, due to the differences in Amiga and PC (in this case: GUS) hardware,
! 184: this isn't really feasible. You _might_ get something like this to work in
! 185: some special cases (ProTracker modules might be a case that could be made
! 186: to work), but I don't think you can come up with something that emulates
! 187: all of the Amiga sound hardware.
! 188: The problem is that by just examining the values a program writes into the
! 189: audio hardware registers, you can hardly figure out what a program is
! 190: trying to do, and what it is going to do in the future. In contrast to
! 191: that, it's easy to write a SoundTracker module player for GUS cards because
! 192: you know exactly what you are playing, and how you have to do it.
! 193: (That doesn't mean you can't use the GUS for sound output; you just can't
! 194: use it to _speed up_ the sound output)
1.1 root 195:
196: Q: Emulating all the hardware is a bad idea. Why don't you just emulate the
197: OS? After all, that's what makes the Amiga the Amiga.
198: A: Short answer: I disagree.
199: Long answer: The OS is half of what makes the Amiga the Amiga. It is a very
200: nice OS, and there are some features that I miss in any other OS, but it is
201: also severely lacking in terms of (for example) memory protection and
202: filesystem performance.
203: The other thing that made the Amiga special back in the 1980s is the custom
204: chip architecture. If you look into old (1985) computer magazines, you will
205: find that the capabilites of the Amiga OS are only mentioned as a side
206: note, because people were not aware that it was revolutionary for a home
207: computer. They were aware, though, that the Amiga could display 4096 colors
208: at the same time and that it had a blitter and a copper that could do all
209: sorts of stuff, like bouncing balls for instance. And I think it was the
210: superiority of the hardware that made the Amiga a success.
211: I see UAE as a program that is similar to C64 emulators: it allows you to
212: run some old games and other programs that you can't replace with better
213: equivalents on the PC. As such, it can already be used to run non-action
214: games (like Monkey Island or Bard's Tale) at a satisfactory speed. Faster
215: CPUs will eventually make it possible to run action games, just like faster
216: CPUs have made it possible to emulate a C64 at full speed on a PC. UAE is
217: not (primarily) meant for the Amiga PowerUser who is running high quality
218: applications on his A4000 with a 68060 board, but for people like me who
219: switched from an A500 to the PC a few years ago because they wanted to make
220: money by developing software.
221: Besides, emulating an OS is far more difficult IMHO. Especially if the
222: platform you are emulating it on is completely different than the platform
223: that is being emulated. You'd have to mess with endianness conversions and
224: other nightmares. The AmigaOS wasn't designed with portability in mind
225: either.
226:
1.1.1.2 ! root 227: Q: How fast is it?
! 228: A: This is the most difficult question to answer. The easy way to answer is
! 229: "It depends", but I'll try to do better. All timings I give here were
! 230: measured on my machine, a P90, using SVGAlib, with the FASTER_CPU and
! 231: DONT_WANT_SOUND options. Note that different versions of UAE generally run
! 232: at different speeds, so take these timings with a grain of salt.
! 233: The MC68000 emulation is more than twice as fast as a real A500. I measured
! 234: this by letting PowerPacker try to compress itself (it already was
! 235: compressed). It took UAE about 6 minutes, my A500 took about 15. You can
! 236: get about twice the speed of an A500 for this type of program (not much
! 237: graphics activity) or if you set the frame skip rate to a high value.
! 238: For games and demos, the CPU speed does not matter, but the average frame
! 239: time is important. UAE can calculate this automatically. The SVGAlib
! 240: version gives the number when you exit the emulator, to obtain the value
! 241: with the X version you need to interrupt it and type "c" in the debugger.
! 242: A real A500 has a constant frame time of 20ms (50 Hz).
! 243: If you have a game/demo that has lots of blitter activity, many copper/
! 244: sprite effects, dual playfields and scrolling, no one can help you.
! 245: Fortunately, this case is extremely rare. Normal games that have a number
! 246: of blitter objects, scrolling and maybe some sprites run at 1/3-1/4 the
! 247: speed of an A500 in the worst case, some run at 1/2 the speed. Lowering
! 248: the frame rate helps enormously here, and at 1/5 frame rate, about
! 249: everything runs somewhere between 50% and 100% the speed of an A500.
! 250: This still isn't the full story (I bet you start to see why the question is
! 251: hard to answer). A real A500 without fast memory gets slowed down to about
! 252: half its speed in Hires 16 color mode. More bitplanes also slow UAE down,
! 253: but not quite as much, so it can be several times faster than an A500 in
! 254: that mode.
! 255: Finally, some remarks about the m68k->i386 code compiler that is available
! 256: in the Linux version of UAE. It shouldn't be used for games, it will
! 257: completely kill your frame rate. It's possible to use it for Workbench
! 258: applications, though, and the frame rate shouldn't be a problem in this
! 259: case.
! 260: I measured PowerPacker the same way as described above, and the time when
! 261: using the compiler is slightly above 1 minute (10-15 times an A500). With
! 262: the USER_PROGRAMS_BEHAVE option, it's as low as 40 seconds. I've also run
! 263: the BeachBall benchmark from AIBB 6.5. This takes around 10 minutes on an
! 264: A500, UAE is 3 times faster with the compiler. For some benchmarks that
! 265: use function calls heavily, the compiler isn't a win (although the current
! 266: version should no longer be slower like previous ones). I have little
! 267: "real world" data, please let me know if you made any experiences with the
! 268: compiler.
! 269:
! 270: Q: How can I make it faster?
! 271: A: Run the emulator in the lowest screen mode (320x200), set it to 256 colors,
! 272: make sure aspect correction is disabled, and set the frame rate to every 3rd
! 273: frame. Finally, disable sound (if you have a version that lets you compile
! 274: your own executable, set "DONT_WANT_SOUND" in config.h). It won't look very
! 275: nice, but it will run as fast as your machine allows.
! 276: If you are running the X version, make sure you have commented
! 277: DONT_WANT_SHM in config.h. This option is "safer", but makes the emulator
! 278: very slow. Even better, when you run configure, say "configure
! 279: --enable-dga" if your X server (XFree86 3.2 or higher) supports it.
! 280:
! 281: Q: What do I do if a game/demo/application doesn't work?
! 282: A: If you're trying to run a game or a demo, enable some SLOW RAM, and try
! 283: running it again. Some older software has compatability problems which SLOW
! 284: RAM can sometimes fix. If it's an application, check for obvious things
! 285: like Kickstart version requirements, RAM, etc. Also make sure the software
! 286: you're trying to run isn't for AGA equipped machines.
! 287:
! 288: Q: Will there be a Windows version?
! 289: A: Several people have mailed me in the past that they had started porting
! 290: UAE to WinNT/Win95. I never heard from most of them again. I assume they
! 291: found out that Windows sucks hard.
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