Retroarch: Can I use compressed files and what essential emulators am I missing?

Okay so I have recently started playing around with retroarch on my N3DS 11.3. I have CFW Luma and A9LH installed. I'm using the latest stable build of Retroarch 1.4.1.

so far compatibility seems great and, I've tested these emulators.

• Snes9x (Snes) 2002 seems the best speeds.

• FMSX (MSX/2+)Only roms seem to be working, no disk or tape files appear. good speeds

• Mednafen Pc Engine (turboGrafx 16) Great speeds, Have not tested CD rom games as of yet.

• Mednafen Neo Geo Pocket (NeoGeo Pocket Colour) This seems to work well enough for colour games only.

• Nestopia (NES) works great but couldn't figure out FDS games.

• Genesis Plus GX (Master System, GG and Genesis/MegaDrive/mega Cd) I find this the best emulator for all 8-16 bit sega and with FM sound enhancement for SMS. I haven't figured out CD games yet.

• PicoDrive (master System, MegaDrive/32X/mega Cd) 32x seems really laggy and again have not tested CD games yet.

Overall I'm pretty pleased with what I've tried so far, However I was wondering if its possible for retroarch to use compressed rom files ? I have tried using compressed files for nestopia, snes9x and genesis plus GX, although it worked on retroarch for windows, the same files did not work for the N3DS.
Would I need to compress them in a certain way ?

How is Mega CD compatibility ? and how about Pc Engine can it emulate super Grafx also ?
What other emulators are worth getting, what essentials would you say am I missing ?

 

Yeah i noticed that thread is in need of some serious updating, it states in the OP for the retroarch nightlies thread that Catsfc is the best Snes emu but its not even included on the new stables or nightlies.
I will get around to trying everything out at some point, I'm just waiting until I can afford to buy a 64gb sd card, maybe I will make a compatibility list or something like that. if it's helpful and/or I have the time ?

 

Is the PS1 Emu any good, I heard its really slow ?
was interested to try it out, but if its running at like 25-50 fps I cant really deal with, so wont bother trying. and heard it runs around 30 fps.

I came a across Handy3DS today and was curious to look into that, have never really given the Lynx much thought before.
Might be a good excuse to get to grips with its library.

I will have a go with the FDS, and see how I get on. I also want to find out if Nestopia plays the extra famicom sound chip of castlevania III or any others?
PCE CD seems to work the same as it did on the DS (where it worked amazingly I must say) , so should be straight forward to sort that out.
I'm really wanting to try out mega CD and its few bizarre games.

 

Retroarch 1.5 out today,

Okay so I managed to get sega and Turbo GraFx CD working Fine have only tried a few,

Any suggestions for best Sega CD games?


so far I have.....

Final Fight, Popful Mail, Snatcher and sonic CD.

Guess I'll need Echo the Dolphin and Road Avenger, Flashback is that in CD form? I don't know off the top of my head,
any others?