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# Virtual Boy Documentation

Last updated January 2, 2024
Valid as of 1.32.0-UNSTABLE

Table of Contents:

- Introduction
- Custom Palettes
- Settings Reference

## Introduction

Virtual Boy emulation in Mednafen is original code, except for an extremely modified(optimizations, bug fixes, and better all-around emulation) V810 emulator core taken from Reality Boy years ago for PC-FX emulation.

Virtual Boy ROM images must each have an extension of ".vb" or ".vboy" to be recognized as such. Mednafen versions prior to 0.9.13 allowed ".bin" as well, but this conflicts with the Sega Megadrive emulation module.

Due to how the left+right views are transformed into a single image, enabling most of the image filter effects(bilinear interpolation, OpenGL pixel shaders, special scalers, etc.) is not recommended. However, they will work properly with the "cscope" and "sidebyside" 3D modes, and may work tolerably with the "anaglyph" 3D mode. This limitation may be corrected in the future by refactoring the 3D mode mixing out to the driver side, post individual filtering for each left/right view; however, this would significantly negatively impact performance.

To use the "hli" mode with a "Line Interlaced 3D" monitor, you'll want to set "vb.yscale(fs)" to 1, "vb.liprescale" appropriately, and "vb.xscale(fs)" to 2 multiplied by the value of "vb.liprescale".

NOTE: The "hli" and "vli" modes will not work properly in windowed video output mode; you may need to adjust the window's position to get the lines to line up correctly for the 3D effect to work.

## Custom Palettes

Global Filename: | Description:
--- | ---
vb.pal | VB LED Active Time; 256 left, 256 right. If only 256 triplets are present, then they will be used for both left and right views. When the custom palette's right view colors are the same as the left view colors(either explicitly, or when using a 256-entry custom palette), and anaglyph 3D mode is active, then the custom palette will not be used. 256 or 512 RGB triplets

## Settings Reference

Caution: Any settings that change emulation behavior as seen from the emulated game are shown with the setting name bolded in the table. One should be conscious of these settings if one has changed them from the default values when using network play or movies, as they can cause desychronizations if not set the same among hosts(or between the recording emulator and the playing emulator).

Setting: | Value Type: | Possible Values: | Default Value: | Description:
--- | --- | --- | --- | ---
vb.3dmode | enum | anaglyph cscope sidebyside vli hli left right | anaglyph | 3D mode. anaglyph - Anaglyph Used in conjunction with classic dual-lens-color glasses. cscope - CyberScope Intended for use with the CyberScope 3D device. sidebyside - Side-by-Side The left-eye image is displayed on the left, and the right-eye image is displayed on the right. vli - Vertical Line Interlaced Vertical lines alternate between left view and right view. hli - Horizontal Line Interlaced Horizontal lines alternate between left view and right view. left - Left View Only Show only the left view. right - Right View Only Show only the right view.
vb.3dreverse | boolean | 0 1 | 0 | Reverse left/right 3D views.
vb.allow_draw_skip | boolean | 0 1 | 0 | Allow draw skipping. If "vb.instant_display_hack" is set to "1", and this setting is set to "1", then frame-skipping the drawing to the emulated framebuffer will be allowed. THIS WILL CAUSE GRAPHICAL GLITCHES, AND THEORETICALLY(but unlikely) GAME CRASHES, ESPECIALLY WITH DIRECT FRAMEBUFFER DRAWING GAMES.
vb.anaglyph.lcolor | integer | 0x000000 through 0xFFFFFF | 0xffba00 | Anaglyph maximum-brightness color for left view.
vb.anaglyph.preset | enum | disabled red_blue red_cyan red_electriccyan red_green green_magenta yellow_blue | red_blue | Anaglyph preset colors. disabled - Disabled Forces usage of custom anaglyph colors. red_blue - Red/Blue Classic red/blue anaglyph. red_cyan - Red/Cyan Improved quality red/cyan anaglyph. red_electriccyan - Red/Electric Cyan Alternate version of red/cyan red_green - Red/Green green_magenta - Green/Magenta yellow_blue - Yellow/Blue
vb.anaglyph.rcolor | integer | 0x000000 through 0xFFFFFF | 0x00baff | Anaglyph maximum-brightness color for right view.
vb.cpu_emulation | enum | fast accurate | fast | CPU emulation mode. fast - Fast Mode Fast mode trades timing accuracy, cache emulation, and executing from hardware registers and RAM not intended for code use for performance. accurate - Accurate Mode Increased timing accuracy, though not perfect, along with cache emulation, at the cost of decreased performance. Additionally, even the pipeline isn't correctly and fully emulated in this mode.
vb.default_color | integer | 0x000000 through 0xFFFFFF | 0xF0F0F0 | Default maximum-brightness color to use in non-anaglyph 3D modes.
vb.disable_parallax | boolean | 0 1 | 0 | Disable parallax for BG and OBJ rendering.
vb.input.instant_read_hack | boolean | 0 1 | 1 | Input latency reduction hack. Reduces latency in some games by 20ms by returning the current pad state, rather than latched state, on serial port data reads. This hack may cause some homebrew software to malfunction, but it should be relatively safe for commercial official games.
vb.instant_display_hack | boolean | 0 1 | 0 | Display latency reduction hack. Reduces latency in games by displaying the framebuffer 20ms earlier. This hack has some potential of causing graphical glitches, so it is disabled by default.
vb.ledonscale | real | 1.0 through 2.0 | 1.75 | LED on duration to linear RGB conversion coefficient. Setting this higher than the default will cause excessive white crush in at least one game. A value of 1.0 is close to ideal, other than causing the image to be rather dark.
vb.liprescale | integer | 1 through 10 | 2 | Line Interlaced prescale.
vb.sidebyside.separation | integer | 0 through 1024 | 0 | Number of pixels to separate L/R views by. This setting refers to pixels before vb.xscale(fs) scaling is taken into consideration. For example, a value of "100" here will result in a separation of 300 screen pixels if vb.xscale(fs) is set to "3".

Setting: | Value Type: | Possible Values: | Default Value: | Description:
--- | --- | --- | --- | ---
vb.debugger.disfontsize | enum | 5x7 6x9 6x12 6x13 9x18 | 5x7 | Disassembly font size. Note: Setting the font size to larger than the default may cause text overlap in the debugger. 5x7 - 5x7 6x9 - 6x9 6x12 - 6x12 6x13 - 6x13. CJK support. 9x18 - 9x18; CJK support.
vb.debugger.memcharenc | string |  | shift_jis | Character encoding for the debugger's memory editor.
vb.enable | boolean | 0 1 | 1 | Enable (automatic) usage of this module.
vb.forcemono | boolean | 0 1 | 0 | Force monophonic sound output.
vb.scanlines | integer | -100 through 100 | 0 | Enable scanlines with specified opacity. Opacity is specified in %; IE a value of "100" will give entirely black scanlines. Negative values are the same as positive values for non-interlaced video, but for interlaced video will cause the scanlines to be overlaid over the previous(if the "video.deinterlacer" setting is set to "weave", the default) field's lines.
vb.shader | enum | none autoip autoipsharper scale2x sabr ipsharper ipxnoty ipynotx ipxnotysharper ipynotxsharper goat | none | Enable specified OpenGL shader. Obviously, this will only work with the OpenGL "video.driver" setting, and only on cards and OpenGL implementations that support shaders, otherwise you will get a black screen, or Mednafen may display an error message when starting up. When a shader is enabled, the "vb.videoip" setting is ignored. none - None/Disabled autoip - Auto Interpolation Will automatically interpolate on each axis if the corresponding effective scaling factor is not an integer. autoipsharper - Sharper Auto Interpolation Same as "autoip", but when interpolation is done, it is done in a manner that will reduce blurriness if possible. scale2x - Scale2x sabr - SABR v3.0 GPU-intensive. ipsharper - Sharper bilinear interpolation. ipxnoty - Linear interpolation on X axis only. ipynotx - Linear interpolation on Y axis only. ipxnotysharper - Sharper version of "ipxnoty". ipynotxsharper - Sharper version of "ipynotx". goat - Simple approximation of a color TV CRT look. Intended for fullscreen modes with a vertical resolution of around 1000 to 1500 pixels. Doesn't simulate halation and electron beam energy distribution nuances.
vb.shader.goat.fprog | boolean | 0 1 | 0 | Force interlaced video to be treated as progressive. When disabled, the default, the "video.deinterlacer" setting is effectively ignored with respect to what appears on the screen, unless it's set to "blend" or "blend_rg". When enabled, it may be prudent to disable the scanlines effect controlled by the "vb.shader.goat.slen" setting, or else the scanline effect may look objectionable.
vb.shader.goat.hdiv | real | -2.00 through 2.00 | 0.50 | Constant RGB horizontal divergence.
vb.shader.goat.pat | enum | goatron borg slenderman | goatron | Mask pattern. goatron - Goatron Brightest. borg - Borg Darkest. slenderman - Slenderman Spookiest?
vb.shader.goat.slen | boolean | 0 1 | 1 | Enable scanlines effect.
vb.shader.goat.tp | real | 0.00 through 1.00 | 0.50 | Transparency of otherwise-opaque mask areas.
vb.shader.goat.vdiv | real | -2.00 through 2.00 | 0.50 | Constant RGB vertical divergence.
vb.special | enum | none hq2x hq3x hq4x scale2x scale3x scale4x 2xsai super2xsai supereagle nn2x nn3x nn4x nny2x nny3x nny4x | none | Enable specified special video scaler. The destination rectangle is NOT altered by this setting, so if you have xscale and yscale set to "2", and try to use a 3x scaling filter like hq3x, the image is not going to look that great. The nearest-neighbor scalers are intended for use with bilinear interpolation enabled, for a sharper image, though the "autoipsharper" shader may provide better results. none - None/Disabled hq2x - hq2x hq3x - hq3x hq4x - hq4x scale2x - scale2x scale3x - scale3x scale4x - scale4x 2xsai - 2xSaI super2xsai - Super 2xSaI supereagle - Super Eagle nn2x - Nearest-neighbor 2x nn3x - Nearest-neighbor 3x nn4x - Nearest-neighbor 4x nny2x - Nearest-neighbor 2x, y axis only nny3x - Nearest-neighbor 3x, y axis only nny4x - Nearest-neighbor 4x, y axis only
vb.stretch | enum | 0 full aspect aspect_int aspect_mult2 | aspect_mult2 | Stretch to fill screen. 0 - Disabled full - Full Full-screen stretch, disregarding aspect ratio. aspect - Aspect Preserve Full-screen stretch as far as the aspect ratio(in this sense, the equivalent xscalefs == yscalefs) can be maintained. aspect_int - Aspect Preserve + Integer Scale Full-screen stretch, same as "aspect" except that the equivalent xscalefs and yscalefs are rounded down to the nearest integer. aspect_mult2 - Aspect Preserve + Integer Multiple-of-2 Scale Full-screen stretch, same as "aspect_int", but rounds down to the nearest multiple of 2.
vb.tblur | boolean | 0 1 | 0 | Enable video temporal blur(50/50 previous/current frame by default).
vb.tblur.accum | boolean | 0 1 | 0 | Accumulate color data rather than discarding it.
vb.tblur.accum.amount | real | 0 through 100 | 50 | Blur amount in accumulation mode, specified in percentage of accumulation buffer to mix with the current frame.
vb.videoip | enum | 0 1 x y | 0 | Enable (bi)linear interpolation. 0 - Disabled 1 - Bilinear x - Linear (X) Interpolation only on the X axis. y - Linear (Y) Interpolation only on the Y axis.
vb.xres | integer | 0 through 65536 | 0 | Full-screen horizontal resolution. A value of "0" will cause the current desktop horizontal resolution to be used.
vb.xscale | real | 0.01 through 256 | 2.000000 | Scaling factor for the X axis in windowed mode.
vb.xscalefs | real | 0.01 through 256 | 1.000000 | Scaling factor for the X axis in fullscreen mode. For this setting to have any effect, the "vb.stretch" setting must be set to "0".
vb.yres | integer | 0 through 65536 | 0 | Full-screen vertical resolution. A value of "0" will cause the current desktop vertical resolution to be used.
vb.yscale | real | 0.01 through 256 | 2.000000 | Scaling factor for the Y axis in windowed mode.
vb.yscalefs | real | 0.01 through 256 | 1.000000 | Scaling factor for the Y axis in fullscreen mode. For this setting to have any effect, the "vb.stretch" setting must be set to "0".