
KNOWNBUG.TXT
$Id: KNOWNBUG.TXT 1.8 1997/07/12 05:19:46 MCUDDY Exp $
(VERSION 1.1)

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	This file contains known bugs in the KEM emulator.  Please do not
	report known bugs.
	
	                 !!! ALSO: READ THE FAQ !!! 
	
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	The file is divided up into two main sections:  the first lists
	bugs in the core systems of the emulation, and the second relates
	to game-specific bugs.
	
	It is important to note that when I say "emulation" I am talking 
	about the game that is running inside of the "emulator" -- the
	"emulator" is the program that I wrote, the "emulation" is the
	software that would be running on real hardware (i.e.: the code
	in the roms).
	
    CORE SYSTEMS:
    -------------
    
        KEM FRAMEWORK
	-------------
	
	    * If the emulator crashes, it does not do so gracefully;
	      it leaves the screen in graphics mode.  You should
	      be able to just type 'mode co80' and press ENTER and
	      have the screen come back.  Does anybody know a 
	      way to catch DOS4/GW faults?
	
	    * If you are running under Win95, don't start KEM in a 
	      window.  It will likely crash your system (or at least
	      confuse the hell out of Win95).
	      
	    * No joystick support.  The mouse, keyboard, and logitech 
	      Wingman Warrior are supported; use JOYEMU for joystick
	      support. 
	      
	    * The first key pressed will sometimes cause a click on 
	      the PC's speaker
	      
	Z80 CPU CORE
	------------
	    
	    * Cpu "T" states are not counted, only instructions.
	    
	"KONAMI" EMULATOR (GYRUSS, TIMEPILOT, AND POOYAN) CORE
	------------------------------------------------------
	
	    * Volume control and panning for individual PSGs do not work 
	      anymore since I've divorced SEAL for SBDRV (SBDRV doesn't 
	      support stereo, and the mixing routines that I wrote do 
	      not support volume control, yet).
	      
	    * These games are extra slow in the "SCROLLING" modes,
	      you should use a mode that doesn't scroll for maximum speed.
	      (i.e.: x and y greater than 512; the default of 800x600
	      works nicely)
	      
	MCR EMULATOR CORE
	-----------------
	
	    * Clock speed not correct; fps for "tron" is near 30, and fps for
	      "2tigers" is near 45 - 50 ... which is right?  probably has to
	      do with broken CTC emulation.
	      
	    * Audio output oscillators not implemented, nor do I ever think
	      that they will be; this hardware added some vibrato to various
	      sounds at a programmable rate.
	      
	    * Video board emulation needs a "gamma correction" factor 
	      applied; some dark colors are too dark, some bright colors, 
	      too bright (and it varies by SVGA card).
	      
	    * The MCR emulation reports "sound board error";  this 
	      varies by game and host-system cpu speed; it has to do with
	      an assumption in the games' software that both CPUs run at the
	      same speed; in the emulator, they do not: for performance 
	      reasons, the audio CPU is run in "bursts" since it normally
	      spends most of it's time waiting for an interrupt.  when that
	      time arrives, I run the CPU until it gets back into the 
	      wait-for-an-interrupt loop.
	      
	    * The MCR sprite engine does not handle the sprite priority 
	      color bits..  this shows up as red blobs over the doorways
	      on Tapper.
	      
	"BLUE PRINT" CORE
	-----------------
	
	    * This core should be able to run a few other games -- bally
	      didn't seem to make very many "one-off" games on a 
	      particular set of hardware, but I need to know what 
	      games were based on the same or similar hardware
	      
	    * The Z80 emulation is too slow, so the "realtime" clock 
	      can interrupt the cpu at the wrong times causing
	      the emulation to crash; I've got a temporary work 
	      around until I work with Neil to finish the asm z80 
	      core.
	      
	    * There are some sprite clipping problems (the girl and 
	      monster running across the screen flash to the upper 
	      corners)
	      
	    * HFlipping and VFlipping of sprites is not implemented.
	    
	PSG EMULATION CORE
	------------------
	
	    * Some low-frequency and high-frequency sounds do not seem
	      to come out right.  
	      
	    * The AY-3-8910 PSG generates yucky-old-square-waves for 
	      output. Most system designers when using this chip would
	      put a Resistor/Capacitor (R/C) filter on the output to
	      tone down the harmonics; this R/C filtering is not
	      emulated (yet!)
	
	"SVGA" Driver
	-------------
	
	    * The 800x600 VESA mode does not work correctly on some matrox 
	      cards;  I've been told that an updated driver from matrox
	      will fix this problem.  
	      
	      *POSSIBLE FIX* Starting in version 1.1, this should be fixed.
	      Please let me know if it isn't.
	      
	    * S3VBE from Dietmar Meschede is reported to have some problems
	      with KEM's SVGA driver.  I don't have an S3 to check it out
	      on.
	      
	    * I've heard that running any of the MCR games with 
	      some CIRRUS LOGIC based cards (CL5224, w/1MB) can cause 
	      the whole computer to reboot.
	      
	      *FIX* get the latest drivers from cirrus logic!
	      
    SPECIFIC GAME BUGS
    ------------------
    
        BLUE PRINT
	----------
	    
	    * See "BLUE PRINT CORE" above.
    
	GYRUSS
	------
	    
	    * Sometimes sprites "flicker" for one frame of animation, and
	      then jump back to thier correct positions ... this seems
	      to happen on slower machines more often than fast ones; I 
	      suspect it's synchronization problems related to the 
	      (relatively) slow Z80 CPU emulation
	      
	    * There's a "high pitched" sound when warping to planets 
	      (depending on factors such as the phase of the moon, it 
	      could be a low pitched sound) ... what the hardware is 
	      doing here is cycling the audio frequency very quickly high 
	      and low, and turning on and off external filters which make 
	      a neat pulsing sound-effect on a real Gyruss. If you have a
	      really beefy machine (PPro, P166+) you can up the audio
	      update rate to about 1024 and you'll be able to hear
	      some of the modulation ... otherwise, you just have to 
	      put up with the high-pitched sound.
	      
	    * The wave-attack sound is not generated (same reason as above)
	    
	    * The player-ship-firing sound is not generated (same reason as
	      above)
	    
	    * The low-frequency "siren" sound that is a constant on the 
	      real game is not generated. (dunno why)
	      
	    * The last player ship is never completely erased from the
	      bottom of the screen. This is actually an off-by-one bug 
	      in GYRUSS, trying to display the ships remaining "off of the
	      screen" (on a properly adjusted "ARCADE" monitor ;-) 
	      This can be fixed by using the "Clipping" driver;  the 
	      clipping driver is a little slower than the non-clipping 
	      driver.  see data\gyruss.gam ...
	      
	TIME PILOT
	----------
	
	    * As of 1.1b4, because of the sprite-rework, the clipping
	      of the cloud sprites looks really bad.
	    
	    * The colors are wrong; really wrong.  There are 64 four-color 
	      sprite palettes and 64 four-color character palettes; you try 
	      to get them all correct from memory ;-)  (MAME suposedly
	      has a perfect palette; I have the palette file; look for 
	      it in a future release).
	      
	    * Some people have reported "stuck" bullets on the screen.  
	      I have not seen this personally. This may be related to 
	      AWE-32 and SEAL eating up too much CPU time. KEM might
	      not have this problem.
	      
	    * On one P133 with SB/AWE32, I've had a report of a sprite
	      flicker problem that sounds like the gyruss sprite-flicker
	      problem;  I'm pretty sure that this one is related to 
	      the AWE eating up too much CPU ...
	      
	
	POOYAN
	------
	
	    * Most of the colors are wrong.
	    
	    * Pooyan doesn't save high-scores, yet.
	      
    	DOMINO MAN
	----------
	
	    * None known
	
	
	SATAN'S HOLLOW
	--------------
	
            * It has been reported that sometimes bridge-pieces get left
	      behind when the player ship is shot while carrying a
	      piece.  I have not been able to reproduce this.
	
	TRON
	----
	
	    * Some glitches in the top few lines of the screen on the
	      tank level; I've been told that this happens on a real 
	      machine, so KEM is bug-for-bug compatible ;-)
	      I think that the programmers ran out of RAM and used that
	      line of the screen as scratch-pad space assuming that it would
	      be clipped by the arcade monitor
	      
	    * When beaming up into I/O tower, TRON's arm and DISC get 
	      drawn in the upper left-hand corner of the screen as they
	      are "clipped" off of the top of the screen.  I've been
	      told that this happens on the real machine, too.
	      
	TWO TIGERS
	----------
	
	    * Game does not run at correct speed; with FPS (-f) set to 30,
	      the game is too slow, at 48 it's about right, but since TRON
	      is a drop-in-replacement for this none-too-popular game, I 
	      suspect that the timer-rate for the MCR/II system board is
	      broken.
	      
	JOURNEY
	-------
	
	    * The Blobs in the second part of the "Jonathan Cain" game
	      (Piano) are colored wrong ... this is the same bug that
	      causes the red squares on tapper; the pink bits are supposed to
	      be masked.
	    
	TAPPER
	------
	
	    * It's reported that tapper crashes when reaching the "alien"
	      level.  I'm not that good, so I haven't gotten that far ;-)
	      It's probably a machine speed issue, since I've had many 
	      reports that people have been able to get past the alien
	      level.
	      
	    * The MCR sprite engine does not handle the sprite priority 
	      color bits..  This shows up as red blobs over the doorways.
	      
	      
	DISCS OF TRON
	-------------
	
	    * It's reported that DOT crashes when you reach the first 
	      level where you can move the aimer up and down.  Like TAPPER,
	      I'm not that good, so I haven't gotten that far.
	      
	    * The "talk" part of the "Squawk & Talk MCR/II" is not 
	      emulated.
	      
	TIMBER 
	------
	
	    * None known
	    
    	
	DEMOLITION DERBY
	----------------
	
	    * Setting the "2-player standup" dipswitch seems to have no
	      effect on the screen layout.
	      
	    * Can't play in "4-player" mode cause the MCR input section
	      of the emulator doesn't support the mux'ing of controls
	      used by the game.
	    
	    * No sound.
	
	RAMPAGE
	-------
	
	    * No sound.
	    
        KICKMAN
	-------
	 
	    * The input system is tricky; the orig. game used a trak ball
	      with a 4-bit resolution; this is quickly overflowed by a 
	      mouse input (even with lots of scaling)  I think it reads it
	      twice, after a fixed delay, and uses that to guage a speed
	      for the trak ball, but I'm not sure yet. (KICKMAN works almost
	      flawlessly with a logitech wingman warrior!)
	      
	SOLAR FOX
	---------
	
	    * None Known
	    
	WACKO
	-----
	
	    * None Known
