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.

Features¶

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

The PicoDrive core has been authored by

notaz
fdave

The PicoDrive core is licensed under

Non-commercial

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

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

Extensions¶

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

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

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

Features¶

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

Feature	Supported
Restart	✔
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 library name is 'PicoDrive'

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

Frontend's Save directory

File	Description
*.srm	Cartridge backup save

Frontend's State directory

File	Description
*.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 base width is 320
The PicoDrive core's base height is 224
The PicoDrive core's max width is 320
The PicoDrive core's max height is 240
The PicoDrive core's core provided aspect ratio is 10/7 when the 'Core-provided aspect ratio' core option is set to PAR
The PicoDrive core's core provided aspect ratio is 4/3 when the 'Core-provided aspect ratio' core option is set to 4/3
The PicoDrive core's core provided aspect ratio is 5/4 when the 'Core-provided aspect ratio' core option is set to CRT

Loading Sega CD games¶

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:

 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 settings.

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.

User 1 - 2 device types¶

The PicoDrive core supports the following device type(s).

None - Input is disabled - Can be switched to using the Input device core options.
3 button pad - Joypad - Can be switched to using the Input device core options.
6 button pad - Joypad - Can be switched to using the Input device core options.
SMS pad - Joypad - Is automatically switched to when a Sega Master System game is loaded.

Joypad¶

User 1 - 2 input descriptors	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

RetroPad Inputs	User 1 - 2 input descriptors	SMS pad
	Button 1 Start	Button 1 Start
	Button Pause	Button Pause
	D-Pad Up	D-Pad Up
	D-Pad Down	D-Pad Down
	D-Pad Left	D-Pad Left
	D-Pad Right	D-Pad Right
	Button 2	Button 2

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.
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.

External Links¶

Sega 16-bit¶

Last update: 2022-03-31