Cool thx for the replies. As I said I do test on a physical box but Im not the owner of Verbatim so I hope Ill figure out everything with one of the solutions posted here.
I've ben doing a bit of research into this myself, and here's the impression I've gotten from other people (admittedly mostly in the SNES scene, so they may not know PSX as well):
XEBRA is the most accurate PSX emulator CPU-wise. It's also a pain and a half to use, and its audio and video emulation isn't great.
Mednafen, though not quite as accurate as XEBRA for CPU emulation, is still very close, and does a far better job with video and audio emulation. It lacks any sort of useful debugging features, but it's a safe bet that if something works correctly in Mednafen it will work correctly on actual hardware. That said, it's probably easier to use the Mednafen-PSX core in
Retroarch than Mednafen itself.
no$psx is less accurate than either, but the debugging tools that halkun mentioned are damn useful (as is the case with all no$ software). It's also worth noting that it's fast as hell, and you will have no trouble achieving full speed on pretty much any machine.
The tool-assisted speedrun community prefers
PSXjin. It's not as accurate as Mednafen or XEBRA, but it's still above average, and its recording features could well prove useful for testing/debugging (though that was not their main purpose). It's got a friendly UI for ram watching, if that's helpful (I assume no$psx does too, though I haven't really touched any of its debugging stuff).
PCSX-Reloaded is still in surprisingly active development and might be worth checking out, but without debugging tools on no$psx's level, or accuracy on Mednafen/XEBRA's level, it probably isn't worth the time. It's worth noting that PSXjin was derived from PCSX-Rerecording, which in turn was derived from this project some time ago; this one is probably more accurate at this point, but not considerably so; they do still share a LOT of older code.
You should quite frankly avoid pSX, ePSXe, bleem!, FPSE, and pretty much any other PSX emulator you find. These haven't been updated in years (except ePSXe which received small updates like once a year, and still isn't particularly good compared to what's out there), are unlikely to see major fixes or improvements in the future, and may be okay for playing games but are near useless for serious testing.
