Sega - MS/MD/CD/32X (PicoDrive)

Background

PicoDrive is an open-source Sega 8/16 bit and 32X emulator which was written having ARM-based handheld devices in mind.

  • Supports 32x emulation.
  • Designed to run on weak devices.

Author/License

The PicoDrive core has been authored by

  • notaz
  • fdave

The PicoDrive core is licensed under

A summary of the licenses behind RetroArch and its cores have found here.

Extensions

Content that can be loaded by the PicoDrive core have the following file extensions:

  • .bin
  • .gen
  • .smd
  • .md
  • .32x
  • .cue
  • .iso
  • .sms
  • .68k

Databases

RetroArch database(s) that are associated with the PicoDrive core:

BIOS

Required or optional firmware files go in the frontend's system directory.

Filename Description md5sum
bios_CD_E.bin MegaCD EU BIOS - Required e66fa1dc5820d254611fdcdba0662372
bios_CD_U.bin SegaCD US BIOS - Required 2efd74e3232ff260e371b99f84024f7f
bios_CD_J.bin MegaCD JP BIOS - Required 278a9397d192149e84e820ac621a8edd

Features

Frontend-level settings or features that the PicoDrive core respects.

Feature Supported
Restart ✔
Screenshots ✔
Saves ✔
States ✔
Rewind ✔
Netplay ✔
Core Options ✔
RetroAchievements ✔
RetroArch Cheats ✔
Native Cheats ✕
Controls ✔
Remapping ✔
Multi-Mouse ✕
Rumble ✕
Sensors ✕
Camera ✕
Location ✕
Subsystem ✕
Softpatching ✕
Disk Control ✔
Username ✕
Language ✕
Crop Overscan ✕
LEDs ✕

Directories

The PicoDrive core's internal core name is 'PicoDrive'

The PicoDrive core saves/loads to/from these directories.

Frontend's Save directory

  • 'content-name'.srm (Cartridge backup save)

Frontend's State directory

  • 'content-name'.state# (State)

Geometry and timing

  • The PicoDrive core's core provided FPS is 60 for NTSC games and 50 for PAL games.
  • The PicoDrive core's core provided sample rate is 44100 Hz
  • The PicoDrive core's core provided aspect ratio is dependent on the 'Core-provided aspect ratio' core option.

Loading Sega CD content

When loading Sega CD games, PicoDrive needs a cue-sheet that points to an image file. A cue sheet, or cue file, is a metadata file which describes how the tracks of a CD or DVD are laid out.

If you have e.g. foo.bin, you should create a text file and save it as foo.cue. If the Sega CD game is single-track, the cue file contents should look like this:

1
2
3
 FILE "foo.bin" BINARY
  TRACK 01 MODE1/2352
   INDEX 01 00:00:00

After that, you can load the foo.cue file in RetroArch with the PicoDrive core.

Certain Sega CD games are multi-track, so their .cue files might be more complicated.

Here's a cue file example done with Lunar - Eternal Blue (USA)

Core options

The PicoDrive core has the following option(s) that can be tweaked from the core options menu. The default setting is bolded.

Settings with (Restart) means that core has to be closed for the new setting to be applied on next launch.

  • Input device 1 [picodrive_input1] (3 button pad/6 button pad/None)

    Choose which kind of controller is plugged in slot 1.

  • "Input device 2 [picodrive_input2] (3 button pad/6 button pad/None)

    Choose which kind of controller is plugged in slot 2.

  • No sprite limit [picodrive_sprlim] (disabled/enabled)

    Enable this to remove the sprite limit.

  • MegaCD RAM cart [picodrive_ramcart] (disabled/enabled)

    Emulate a MegaCD RAM cart.

  • Region [picodrive_region] (Auto/Japan NTSC/Japan PAL/US/Europe)

    Force a specific region.

  • Core-provided aspect ratio [picodrive_aspect] (PAR/4/3/CRT)

    Choose the core-provided aspect ratio. RetroArch's aspect ratio must be set to Core provided in the Video seetings.

Core-provided aspect ratio - PAR

Core-provided aspect ratio - 4/3

Core-provided aspect ratio - CRT

  • Show Overscan [picodrive_overscan] (disabled/enabled)

    Crop out the potentially random glitchy video output that would have been hidden by the bezel around the edge of a standard-definition television screen.

Show Overscan - Off

Show Overscan - On

  • 68k overclock [picodrive_overclk68k] (disabled/+25%/+50%/+75%/+100%/+200%/+400%)

    Overclock the emulated 68k chip

  • Dynamic recompilers [picodrive_drc] (enabled/disabled)

    Enable dynamic recompilers which help to improve performance. This core option is not available on all hardware.

  • Audio filter [picodrive_audio_filter] (disabled|low-pass)

    Enable a low pass audio filter to better simulate the characteristic sound of a Model 1 Genesis.

Attention

This option is ignored when running Master System and PICO titles. Only the Genesis and its add-on hardware (Sega CD, 32X) employed a physical low pass filter.

  • Low-pass filter % [picodrive_lowpass_range] (60|65|70|75|80|85|90|95|5|10|15|20|25|30|35|40|45|50|55)

    Specify the cut-off frequency of the audio low pass filter. A higher value increases the perceived 'strength' of the filter, since a wider range of the high frequency spectrum is attenuated.

Controllers

The PicoDrive core supports the following device type(s) in the controls menu, bolded device types are the default for the specified user(s):

User 1 - 2 device types

  • None - Doesn't disable input.
  • RetroPad - Joypad
  • RetroPad w/Analog - Joypad - There's no reason to switch to this.

Controller tables

Joypad

User 1 - 2 Remap descriptors RetroPad Inputs 3 button pad 6 button pad
B B B
A A A
Mode Mode
Start Start Start
D-Pad Up D-Pad Up D-Pad Up
D-Pad Down D-Pad Down D-Pad Down
D-Pad Left D-Pad Left D-Pad Left
D-Pad Right D-Pad Right D-Pad Right
C C C
Y Y
X X
Z Z

Compatibility

32x games Issue
Brutal Unleashed – Above the Claw Softlocks after the first fight.
FIFA Soccer ’96 Glitched main menu text.
Knuckles’ Chaotix Glitched graphics on the Player Select screen.
NBA Jam Tournament Edition Framerate issues.
NFL Quarterback Club Some menu graphics are missing.
Star Wars Arcade (PAL version) Glitched opening visuals. Cannot get past Press Start screen.
Virtua Racing Deluxe Blinking line during the SEGA logo screen.
World Series Baseball Starring Deion Sanders Crashes when starting a match.
WWF Raw Various graphics are missing.

See also

Sega - Master System - Mark III

Sega - Mega Drive - Genesis

Sega - Mega-CD - Sega CD

Sega - PICO