NEC - PC Engine / SuperGrafx (Geargrafx)¶

Background¶

Geargrafx is an open source, cross-platform, PC Engine / TurboGrafx-16 / SuperGrafx emulator written in C++.

Accurate emulation supporting the entire PCE / SGX catalog
Multi Tap support (up to 5 players)
Controllers:
Standard Gamepad (2 buttons)
Avenue Pad 3 (3 buttons, auto-configured based on game)
Avenue Pad 6 (6 buttons)
Internal database for automatic rom detection
Backup RAM support
Save state support
Retro Achievements support
Adjustable scanline count (224p, 240p, or manual)
RGB or Composite color output
Supported platforms (libretro): Windows, Linux, macOS, Raspberry Pi, Android, iOS, tvOS, PlayStation Vita, PlayStation 3, Nintendo 3DS, Nintendo GameCube, Nintendo Wii, Nintendo WiiU, Nintendo Switch, Emscripten, Classic Mini systems (NES, SNES, C64, etc.), OpenDingux, RetroFW and QNX.

The Geargrafx core has been authored by

Ignacio Sanchez (drhelius)

The Geargrafx core is licensed under

GPLv3

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

BIOS¶

Geargrafx does not require BIOS (bootrom) files to work.

Extensions¶

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

.pce
.sgx
.bin
.rom

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

Features¶

Frontend-level settings or features that the Geargrafx 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 Geargrafx core's library name is 'Geargrafx'

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

Frontend's Save directory

File	Description
*.srm	Cartridge battery save

Frontend's State directory

File	Description
*.state#	State

Geometry and timing¶

The Geargrafx core's provided FPS is 59.82
The Geargrafx core's provided sample rate is 44100 Hz
The Geargrafx core's base width is dependent on the content and overscan settings (Without overscan: 256, 341, 512. With overscan: 280, 373, 560)
The Geargrafx core's base height is dependent on the 'Scanline Start' and 'Scanline End' core options.
The Geargrafx core's max width is 560
The Geargrafx core's max height is 242
The Geargrafx core's provided aspect ratio is dependent on the 'Aspect Ratio' core option.

Core options¶

The Geargrafx core has the following options 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.

TurboTap [geargrafx_turbotap] (Disabled|Enabled)

This option enables/disables TurboTap support (up to 5 players).
Aspect Ratio [geargrafx_aspect_ratio] (1:1 PAR|4:3 DAR|16:9 DAR|16:10 DAR)

Select which aspect ratio will be presented by the core.
- 1:1 PAR selects an aspect ratio that produces square pixels.
- 4:3 DAR forces 4:3 aspect ratio.
- 16:9 DAR forces 16:9 aspect ratio.
- 16:10 DAR forces 16:10 aspect ratio.
Overscan [geargrafx_overscan] (Disabled|Enabled)

This option enables/disables overscan (borders). Overscan width is dependent on the content.
Scanline Count [geargrafx_scanline_count] (224p|240p|Manual)

Select which scanline count will be used in emulation.
- 224p forces 224 scanlines.
- 240p forces 240 scanlines.
- Manual lets you set the first and last scanline manually.
Scanline Start (Manual) [geargrafx_scanline_start] (3|0 - 30)

This option will set the first scanline to be displayed. Scanline 0 is the first visible scanline. This option is only available when 'Scanline Count' is set to 'Manual'.
Scanline End (Manual) [geargrafx_scanline_end] (241|220 - 241)

This option will set the last scanline to be displayed. Scanline 241 is the last visible scanline. This option is only available when 'Scanline Count' is set to 'Manual'.
Composite Colors [geargrafx_composite_colors] (Disabled|Enabled)

If enabled, the core will use composite colors instead of RGB colors.
Backup RAM (restart) [geargrafx_backup_ram] (Enabled|Disabled)

This option allows you to disable backup RAM (not recommended).
Force Japanese PC Engine (restart) [geargrafx_force_pce_jap] (Disabled|Enabled)

Allows you to force Japanese PC Engine hardware. This option is not recommended, as many USA games will fail to start if a Japanese system is detected.
Force SuperGrafx (restart) [geargrafx_force_sgx] (Disabled|Enabled)

Allows you to force SuperGrafx hardware. This option is recommended only for content (homebrew) not detected correctly as SuperGrafx.
No Sprite Limit [geargrafx_no_sprite_limit] (Disabled|Enabled)

Enabling this option will remove the sprite limit in a single line. This may cause glitches to occur in certain games. It's best to keep this core option disabled.
Soft Reset [geargrafx_soft_reset] (Enabled|Disabled)

Pressing RUN and SELECT simultaneously on the PCE gamepad will SOFT RESET the console. This is the default hardware behavior. Disable this option if you want the soft reset functionality turned off.
Allow Up+Down / Left+Right [geargrafx_up_down_allowed] (Disabled|Enabled)

Enabling this option allows pressing, quickly alternating, or holding both left and right (or up and down in some games) directions at the same time. This may cause movement based glitches to occur in certain games. It's best to keep this core option disabled.

Joypad¶

PCE Pad (2-button)	Avenue Pad 3 (3-button)	Avenue Pad 6 (6-button)
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
Select	Select	Select
Run	Run	Run
I	I	I
II	II	II
III	III	III
IV		IV
V		V
VI		VI