Dungeon Explorer distorted sprite issues

[ekeeke]

Dungeon Explorer distorted sprite issues

[ekeeke]

It might be an emulation bug, I will check it when I have some time.

[ekeeke]

I can confirm there is a bug with Dungeon Explorer USA release (happens as soon as other sprites than main character appear - happens in demo mode on title screen as well).

Strangely, the PAL release which I used for testing does not have this issue. Also there seems to be a PAL version floating around (.iso) patched to work on US Sega CD and it work fine as well. Also, if you make a savestate on title screen with this patched version then rename the savestate to match the USA version CUE/BIN filename and load it within this version, it now works fine.

So it seems something got messed up during the game loading (before title screen) which later corrupt all moving sprites (main character sprite seems to disappear as well). Strange...

[jamosb]

i will try the (E) version thanks!

On Tue, Jan 20, 2015 at 4:21 AM, ekeeke [email protected] wrote:

I can confirm there is a bug with Dungeon Explorer USA release (happens as
soon as other sprites than main character appear - happens in demo mode on
title screen as well).

Strangely, the PAL release which I used for testing does not have this
issue. Also there seems to be a PAL version floating around (.iso) patched
to work on US Sega CD and it work fine as well. Also, if you make a
savestate on title screen with this patched version then rename the
savestate to match the USA version CUE/BIN filename and load it within this
version, it now works fine.

So it seems something got messed up during the game loading (before title
screen) which later corrupt all moving sprites (main character sprite seems
to disappear as well). Strange...

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#40 (comment)
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[ekeeke]

It should be fixed by e9e56c5

For the record, the USA version of Dungeon Explorer accidentally tries to write to PRG-RAM (on Sega CD side) from the Z80, which corrupts data in RAM if those writes are allowed by the emulator. Those writes should normally be disabled because the SUB-CPU is not being halted, but this was unemulated for some reason.

[jamosb]

So latest version of retroarch should have it or do they take a while to
update you core?

On Sun, Jan 25, 2015 at 7:12 PM, ekeeke [email protected] wrote:

It should be fixed by d11e016
d11e016

For the record, the USA version of Dungeon Explorer accidentally tries to
write PRG-RAM (on Sega CD size) from the Z80 (through 68k banked access),
which corrupt data in RAM if those writes are allowed by the emulator. It
would need some testings on real hardware to confirm it but it's very
likely that writing from Z80 to PRG-RAM is not possible due to timing
issues (this must go through MAIN-68k bus banking then SUB_68K bus
banking).

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#40 (comment)
.

[ekeeke]

There is no automatic or scheduled builds update and we are all people doing this on our free time so I have no idea how much it will take for retroarch core to be "officially" updated.

The purpose of a public repository though is that anyone could actually compile the updated core from here, for any platform, and use it with current version of retroarch. If you don't like to wait, learn how to compile it yourself, it's really not difficult.

[Oggom]

Actually libretro has a buildbot now that provides daily builds for various platforms (including Windows):
http://buildbot.libretro.com/nightly/
The next official stable release is scheduled for this month.