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ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
06896 Gameplay Minor Sometimes Mar 3, 2018, 16:18 15 days ago
Tester Dumple View Status Public Platform MAME (Official Binary)
Assigned To dink Resolution Fixed OS Windows 10 (64-bit)
Status [?] Resolved Driver gottlieb.cpp
Version 0.193 Fixed in Version 0.223GIT Build 64-bit
Summary 06896: krull: Mysterious deaths in Krull cave scene
Description I've been playing Krull via MAME and in the cave sequence (3rd stage), I suddenly die with no apparent cause. This happens once every three times or so. This recording shows a couple of examples, at 1:24 and 6:21


I tried searching and couldn't turn up any reports of this glitch. I haven't played the arcade PCB in 20+ years, so I'm not 100% sure this is an emulation issue.
Steps To Reproduce I've attached a MAME 0.193 .inp file that triggers this twice (once at ~1:24 and once at ~6:21).
Additional Information
Flags
Regression Version
Affected Sets / Systems krull
Attached Files
? file icon krull.inp (185,986 bytes) Mar 3, 2018, 16:18 Uploaded by Dumple
zip file icon krull_die.zip (4,305 bytes) 17 days ago Uploaded by dink
cave scene 0.220 state
zip file icon i86_neg_fix_dink_fbneo.zip (22,319 bytes) 16 days ago Uploaded by dink
i86_neg_fix_dink_fbneo.zip
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Notes
3
User avatar
No.14797
Tafoid
Administrator
Mar 3, 2018, 18:05
Thanks for the report and .inp file. I have to guess if it is anything, it is one of the Slayers about to spawn and it may check for a presence there. It seems to be in the same general area each time.. hard to say. We'll treat it as a bug until proven an actual bug in the game.
User avatar
No.17766
dink
Tester
17 days ago
edited on: 17 days ago
Did a little research on this one:
the mysterious deaths are actually caused an enemy spawning which has a sprite that is not displayed.

How I found out:
play until the cave scene, hitting savestate every second (or so). When a bad death happens, reload the last state, and shoot in diff. directions until you hear a kill sound from the invisible enemy. *state attached*

Debugger hints:
watch 0x0DF1, this is increased right before enemy spawns.

@ 0x1414, the game loops through a huge linked-list of sprites, which jumps around between diff. ram areas a lot (2xx, 3xx, 5xx, 7xx)

This what I got so far, also - in mame 031's whatsnew, it says that [this?/a similar?] bug was fixed by an update to the i86 core, Unfortunately, so much was changed since 0.30 that I'm not sure what it could have been.. I wonder if the bug came back somehow over the years.

Attached State file (krull_die.sta): fastforward to the cave scene in attract mode, then load this state. when you hear the enemy's laser blast, go Down+Right about 1cm, and you'll die from the invisible baddie.
User avatar
No.17767
dink
Tester
16 days ago
I found the problem, here's the fix, including info and references - see attachment: i86_neg_fix_dink_fbneo.zip