KNOWNBUG.TXT $Id: KNOWNBUG.TXT 1.8 1997/07/12 05:19:46 MCUDDY Exp $ (VERSION 1.1) ----------------------------------------------------------------- This file contains known bugs in the KEM emulator. Please do not report known bugs. !!! ALSO: READ THE FAQ !!! ----------------------------------------------------------------- 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