Mednafen 1.26.1 - emu4crt - A13

emu4crt is a Mednafen emulator mod intended to be used on a system connected to a CRT screen, typically a 15kHz TV or an arcade monitor.

It brings "pixel-perfect" rendering by switching host resolution to match emulated system resolution.

• Mednafen modules ported to emu4crt:
  • Sony Playstation
  • Sega Saturn (win64 only)
  • Nintendo NES/Famicon (snes & snes_faust)
  • Nintendo Super NES/Super Famicom
  • NEC PC Engine / PC Engine CD / SuperGrafx (pce & pce_fast)
  • NEC PC-FX
  • Sega Megadrive / Genesis
  • Sega Master System

Many options, meaningless in a CRT screen usage, have been removed from Mednafen in provided emu4crt builds (shaders, etc.).

• Requirements:
  • OS: Windows 32/64bits
  • Video display: OpenGL compatible (the only Mednafen tested renderer).

emu4crt can be use in two modes:

• Native Resolution: Same resolution as emulated system. More custom resolution are required (see below) Generates more resolution changes, which has side effects

• Super Resolution: Requires only four 2560 pixel width resolutions. Avoid some resolution change during emulation

Required resolutions

Native resolutions

• Columns:

	256	320	341	352	368	512	640	704
NES*	X
SNES	X					X
SATURN		X		X			X	X
PSX	X	X			X	X	X
PCE**	X	X				X
PCFX**	X		X
MD/SMS	X	X

• Lines, for each column:

  NTSC modes : 240 and 480 lines @ 60 Hz PAL modes: 288 and 576 lines @ 50 Hz

  * -> 240 and 288 lines only

  ** -> NTSC modes only

Super Resolutions

4 custom resolutions cover all needs for every emulated systems:

	Columns	Lines	Frequency
NTSC	2560	240	60Hz
	2560	480	60Hz
PAL	2560	288	50Hz
	2560	576	50Hz

Custom resolutions can be added on Windows by using Calamity's CRT Emudriver (the best way!), Soft15Hz, Powerstrip, manufacturer drivers...

For CRT Emudriver users:

• emu4crt_NATIVE_RESOLUTIONS.txt contains all resolution informations to be added to VMMAKER's user_modes.ini.
• emu4crt_RESOLUTIONS_SUPER.txt

For testing pupose, emu4crt can be used with a standard PC screen and video drivers in window mode.

Configuration & usage

To enable resolution switch, use "video.resolution_switch" parameter in mednafen.cfg configuration file:

• video.resolution_switch native -> to use native resolution mode
• video.resolution_switch super -> to use super resolution mode
• video.resolution_switch 0 -> to disable resolution switch [DEFAULT MODE]

emu4crt.exe can be placed in an existing mednafen.exe directory, both can share the same configuration file and all ressource files (firmwares, savestates, etc.).

Limits and known issues

• The emulator does not deal with resolution refresh rate. So, to get a deterministic behavior, a resolution must only exist at the expected refresh rate (ie. no 320x240 @ 55Hz).

• Using emu4crt, resolution switch is not seamless process as it is on a console or with some other emulators. At each resolution change, some sound and graphical glitches will occur.

• Graphical glitches can be limited by using full black Windows desktop background and taskbar hidding.

• Windows 7 seems quicker than Windows 10 to switch resolution, at least with CRT Emudriver.

• Emulation logic is preserved, so, expected game compatibility is same as with the Mednafen official release.

If any specific issue with emu4crt mod, of course, do not bother the Mednafen Team!

Contact forum thread: http://forum.arcadecontrols.com/index.php/topic,155264.0.html

Thanks

The Mednafen Team (https://mednafen.github.io) for... Mednafen!

CRT Emudriver's author, Calamity (http://geedorah.com/eiusdemmodi/forum/)

ArcadeControls.com (www.arcadecontrols.com)

No$psx author, Martin Korth for publishing PSX GPU documentation

hotdog963al for his PSX core horizontal centering improvment