jEnesisDS 0.5 - Genesis/Megadrive Emulator for the Nintendo DS

[wraggster]

Lordus has posted an entry in the Neoflash Coding Contest:

Project description:

"jEnesisDS" is a Sega MegaDrive/Genesis Emulator for the Nintendo DS.
It started as a port of my Java Genesis/32X emulator jEnesis. By now, the code has been
completely rewritten and many parts (CPU core, parts of GPU) are written in ARM assembler.

You have to play a bit with the settings to make some games boot or work better.
Some games work faster with "Idle Loop Detection", others without (Castlevania, Gunstar Heroes),
and some games just boot if it is disabled.
The same goes for H-INT emulation. If a game doesnt boot just try changing those options.

Very few games will just boot, if checksum autofixing is disabled (Dynamite Heady, Thunder Force IV).

New in this version:

********
v0.5 *
********
- Implemented save-states (touch slot icons to load/save)
- Extended SRAM compatibility. Story of Thor and Phantasy Star IV should work now.

- Extended "force update" of HW renderer. Fixes Sonic3 intro, Sonic Bonus stage and probably others.
- Fixed sprites showing garbage if more than 64 sprites were displayed. (Comix Zone, Outrun, Sonic, well most games i guess).
- Partial rewrite of sprite handling in the HW renderer. Less slowdowns when a lot of sprites are displayed.
- Implemented better VSync. Fixes temporary speedups after slowdowns.
- Implemented vertical scaling option into HW renderer (horizontal is NOT possible, dont ask!).
Aspect ratio will be incorrect, but makes games more enjoyable (at least in my opinion).
- Implemented screen positioning in HW renderer (touch screen to pause, then use [D-Pad] to scroll.
Push [A] for faster scrolling)

- Rewrote DS interrupt system for HW renderer. Probably less slowdowns, surely safer.

- Added "Fake Z80" option. The faking code can mess up some games (Ghouls n' Ghosts, Aladdin, Cool Spot 2, and others), so it can be turned off now. Interestingly enough, if it is turned off, real Z80 emulation will be executed, BUT just under certain circumstances, to keep games working and not to slow things down. As with other options, some games might depend on a certain setting to boot (Gaiares just boots when this option is set to "off").

How to use:

jEnesisDS uses DLDI for accessing your cards filesystem, so you have to patch the file with the appropriate DLDI patch.

There is no way to edit the key settings yet, so here is the layout:

PAD1:
A="Y"
B="B"
C="A"
X="X"
Y="L"
Z="R"
START="START"
L,R,D,U= directional keys

"SELECT": Enter File Browser (Also accessible by the cartridge icon)

Touch the Joypad icon to enter Setting.
Touch save-slot icons to load/save states (2 slots available)
Touch screen to pause. While in pause mode, use the D-Pad to for
screen positioning in the HW renderer version.

Hope you like it

Download and Give Feedback/Compatability Reports Via Comments

[DanTheManMS]

Glad to see an update to this emulator. Seems to work very well from the limited time I spent testing it.

[koiulpoi]

Woot, works great! Now, all it needs is sound and this emulator is golden!

[Sir_Voe]

Good stuff. I'm not holding my breath for sound, but a speed increase for the SW build is the next thing on my wish list.

[mikeb]

great just needs sounds and what sir voe said

[slaanesh]

I'm curious to know if this emulator is using both Nintendo DS CPUs?

[paul3100]

it is good to see an update and in time i can see sound being implemented , the snes has sound and was technically superior to the genesis/megadrive

paul

[totocorp]

Thank you Lordus ! I run to test it

[Eyedunno]

it is good to see an update and in time i can see sound being implemented , the snes has sound and was technically superior to the genesis/megadrive

paul

Technically superior? Well, yes, except for the main CPU, which was quite a bit faster on the Genesis/Megadrive. That was part of the buzz around the Sonic series.

A Geo Metro is "technically superior" to a 1968 Camaro, but let's see you try and race the two.

[Lordus]

I am currently working on the sound and it looks promising so far...

It is not really true, that the SNES was technically superior, as Eyedunno said. Genesis' main cpu is more powerful and also the sound hardware needs a lot more power to be emulated than the SNES sound hardware.It is absolutely irrelevant in this sense, that SNES games sound better.

This version only uses the Arm9 cpu, except for the basic stuff, like touchscreen and such. (My current development version uses both though, and the next release will hopefully, too).

As for the software renderer, i dont think much can be done. It is already completely written in assembler and uses a pretty fast method as well.
Software rendering just needs a LOT of cpu power.
And of course you want full speed software rendering + sound, right? :P


Forgot to mention in the readme, that you can also set country preferences now. So if a game is multiregion, it wont use the first region specified in the header anymore, but the one you select.


Also:
i got a lot of emails about the previous version, that this and that game doesnt work.
Almost all of those games DID work, just that of course nobody reads the readme. So please try all different settings first, before deciding, that a game doesnt work.
Games over 3MB wont load at all, due to limited ram size. This is on my todo list.