Understanding analog video signals, port types, and terminology is essential when working with CRTs and the Batocera CRT Script. This section defines commonly misunderstood or ambiguous terms used throughout the guide.

Feel free to return to this page at any time for reference.

---

📚 Table of Contents (click to expand)

• 🔌 Active Converter
• 🎮 SCART
  • 🌍 European SCART
  • 🇯🇵 Japanese SCART (JP-21)
• 📺 BNC Cables
• 🎨 Component Video (YPbPr)
• 🟢 YPbPr
• 🎞️ S-Video
• 📼 Composite Video
• 📡 RF Modulator
• 🧃 DisplayPort
• 🧯 Passive Adapters
• 🧰 Transcoder
• 🔠 DVI-I Port
  • ✅ DVI-I (Analog + Digital)
  • ❌ DVI-D (Digital Only)
• 🔵 VGA Port / DSUB-15 / HD-15
• 🧩 VGA Signal
• 🔺 RGB Video Signal
• 🕳️ Horizontal Scan Rate
• 🔄 Vertical Refresh Rate
• 🧠 EDID (Extended Display Identification Data)
• 🔇 Ground Loop Noise Isolator
• 🧲 Ferrite Cores (Ferrite Beads)
• ✅ Related Wiki Pages

---

A device that digitally processes and converts video signals from one format to another (e.g., HDMI to VGA, HDMI to Composite, HDMI to Scart) using internal chips and frame buffers. These are usually inexpensive box-shaped adapters found on Amazon, eBay, or AliExpress, and often introduce:

• ❌ Input lag
• ❌ Scaling artifacts
• ❌ Loss of resolution control
• ❌ Incompatibility with 15kHz CRT signals

🧠 Passthrough vs Scalers:

• ✅ Active converters with resolution passthrough can work in some cases.
• ❌ Converters with built-in scalers, resolution buttons, or fixed output resolutions should be avoided.

🧠 Important Note: Even if some active converters advertise "resolution passthrough" or lack obvious scaling features, they should still be avoided. These devices often:

• Misreport supported resolutions
• Add hidden processing or buffers
• Lack compatibility with low resolutions (e.g., 240p/480i)
• Undermine Batocera’s direct control over output timing

⚠️ Do not confuse these with other devices used in proper CRT setups:

• ✅ Passive VGA to SCART cables – Simply reroute analog RGB signals; no signal processing involved.
• ✅ Sync Combiners (Active SCART Adapters) – Merge separate sync signals (H+V) into composite sync (CSYNC) for SCART, while preserving analog integrity.
• ✅ Transcoders – Convert between analog signal types (e.g., RGBS to YPbPr or S-Video) without introducing lag.
• ✅ Video Amps – Boost and clean analog signals (like RGB), not digital converters; essential for long cable runs or weak outputs.

👉 If it digitally alters the signal format (HDMI/DP to VGA, etc.), it’s likely an active converter and not suitable for CRT use.

⚠️ Only use adapters and cables listed in the official wiki: ➡️ Recommended Adapters, Sync Solutions & Transcoders

---

A 21-pin analog connector widely used in Europe and Japan, but with key differences.

Supports:

• ✅ RGBS (RGB + Sync)
• ✅ Composite video/audio
• ⚠️ S-video and component (YPbPr) in some custom cases (non-standard) ⚠️ Some TVs may accept component (YPbPr) signals via SCART input, but this is non-standard and not widely supported.

👉 Commonly used for connecting retro consoles and computers to consumer CRT TVs using RGB video. 👉 Ideal for RGB setups on consumer CRTs.

---

• Pinout is standardized for RGBS
• Sync typically carried on the composite pin
• Most compatible with sync combiners and passive SCART cables
• Often labeled "AV" or "EXT" on TVs

• Physically identical connector, different pinout
• Incompatible with Euro SCART wiring — never use directly
• Requires proper adapter to avoid damage or no signal
• Commonly found on Japanese TVs and Framemeister

---

⚠️ Warning: Mixing Euro SCART and JP-21 cables or devices without proper adapters can cause signal issues or even damage ports.

🔗 Related:

• ➡️ SCART on Wikipedia
• ➡️ Recommended SCART Adapters

---

Professional-grade coaxial cables used with broadcast monitors such as Sony PVM/BVM units.
Typically used to carry RGB (Red, Green, Blue) signals — often in 3–5 cable sets depending on sync requirements.

👉 Requires a passive VGA-to-BNC adapter to connect from PC video outputs.

🧠 Note: Some monitors do not support separate Horizontal and Vertical sync (RGBHV) and instead require composite sync (RGBS) on the sync input.
In these cases, a sync combiner may be needed to merge H+V sync into a single C-Sync line.

For details on sync methods and adapters, see:

• ➡️ Recommended Adapters, Sync Solutions & Transcoders
• ➡️ BNC connector Wikipedia

---

Three-cable analog video format often color-coded red, green, and blue. Not to be confused with RGB. Used in consoles like the PS2 and DVD players.

• ➡️ Component video Wikipedia

---

Analog component format where Y = luma, Pb = blue minus luma, and Pr = red minus luma. Common in TVs but not directly compatible with RGB equipment.

• ➡️ YPbPr Wikipedia

---

Analog format that separates luma (brightness) and chroma (color) into two lines for improved quality over composite.
👉 Quality sits between composite and RGB, offering a decent compromise when RGB isn’t available..

• ➡️ S-Video Wikipedia

---

Sends color and brightness (luma/chroma) down a single yellow RCA cable.
👉 Low image quality; widely used in retro hardware.

• ➡️ Composite video Wikipedia

---

Converts video signals to RF (TV antenna) signals, used on very old CRTs with only coaxial input.
👉 Found in old VCRs and early gaming consoles.

• ➡️ RF modulator Wikipedia

---

Modern digital output found on most current GPUs.
Cannot output analog natively, but can be used with a DAC (DisplayPort to VGA adapter) for CRT use on supported AMD GPUs and APUs.

🔌 The recommended DAC is the CableDeconn DP to VGA adapter, which uses a Realtek RTD2168/2166 chip to deliver clean, lag-free analog output.

⚠️ Note: This only works with compatible AMD hardware.
It does not work with NVIDIA GPUs or HDMI-only systems.

• ➡️ DisplayPort Wikipedia

---

Simple cable or plug adapters that do not convert or process the signal.
👉 Analog-to-analog or digital-to-digital only — no conversion.

---

Converts one analog format (e.g., RGB) into another (e.g., YPbPr or S-Video) without digital processing.
👉 Usually external and powered, but not active converters.

For details on Recommended Transcoders, see:

• ➡️ Recommended Transcoders

---

DVI-I supports both digital and analog signals. Look for the four extra analog pins around the flat blade.
👉 Ideal for passive VGA adapters and CRT output.

This port can be used with VGA-to-SCART cables and sync combiners, just like a VGA port.

• ➡️ Recommended VGA to SCART Adapters
• ➡️ Digital Visual Interface Wikipedia

_{Compatible with CRT output via passive VGA adapters}

---

_{❗ Not compatible with CRT output — no analog signal present}

---

The VGA port (also known as DSUB-15 or DE-15) is a 15-pin analog connector commonly found on older PCs, CRT monitors, and projectors.

👉 Do not confuse the VGA port (physical connector) with the VGA signal (format).

• The VGA signal refers specifically to an analog RGBHV signal (separate Red, Green, Blue, Horizontal Sync, and Vertical Sync).
• The DSUB-15 connector, however, is just a port — it can be wired to carry other analog signals such as:
  • RGBS (used in arcade and SCART devices)
  • RGsB (sync-on-green)
  • YPbPr (component video on some devices)
• This means not all devices with a VGA/DSUB-15 port output a true VGA signal.

🧠 Example: Some consoles or scalers use a DSUB-15 output, but internally they output RGBS, not VGA — which requires different handling (e.g., a sync combiner or transcoder).

✅ In Batocera CRT setups, we typically use the VGA port to output:

• RGBHV (VGA signal) directly to PC CRT monitors
• Or via sync combiners to convert VGA into RGBS for SCART input
• Or via VGA-to-BNC adapters for use with PVM/BVM monitors (add a sync combiner if your monitor doesn't accept separate sync)
• Or into transcoders to convert VGA into:
  • Component (YPbPr)
  • S-Video
  • Composite, which can then be fed into an RF modulator (e.g. VCR or standalone unit) for use with RF-only TVs

For more info, see:

• ➡️ Types of VGA to SCART Solutions
• ➡️ VGA connector Wikipedia

---

A specific analog signal format designed for PC CRTs. Uses EDID and outputs RGBHV (separate horizontal and vertical sync).
👉 Not directly compatible with SCART or YPbPr without a transcoder or a sync combiner to merge sync signals.

🔗 For SCART setups, VGA is typically converted to RGBS using a sync combiner circuit. See:

• ➡️ Types of VGA to SCART Solutions

---

Analog signal with independent Red, Green, and Blue channels. Requires proper sync (RGBS or RGBHV).
👉 Not the same as VGA or YPbPr.

---

Measured in kHz — how fast each horizontal line is drawn. Typical 15kHz CRTs draw lines ~15,734 times per second.

---

Measured in Hz. This is how many times per second the full screen is redrawn (typically 50Hz PAL or 60Hz NTSC).

---

Metadata sent from a display to a GPU, detailing supported resolutions.

---

Analog CRT monitors manufactured before 1994 typically lack EDID support, as the standard was only introduced that year by VESA. Displays from that era must be configured manually, since they cannot communicate their capabilities to the GPU automatically.

---

A ground loop noise isolator helps eliminate annoying hum or buzz caused by electrical ground loops when connecting your PC’s audio output to other analog devices — common in CRT setups.

These devices contain a small isolation transformer that breaks the direct electrical ground while passing the audio signal cleanly. They only affect audio, not video.

✅ Typical use cases:

• Connecting a PC’s 3.5mm headphone/line-out jack → VGA to SCART cable audio input
• Connecting a PC’s 3.5mm headphone/line-out jack → VideoAMP audio input
• Connecting a PC’s 3.5mm headphone/line-out jack → UMSA (Ultimate SCART Adapter) 2x RCA input
• Connecting a PC’s 3.5mm headphone/line-out jack → arcade cabinet amplifier
• Connecting a PC’s 3.5mm headphone/line-out jack → external shielded speakers
• Or any other adapter, sync solution, or transcoder listed here:
  ➡️ Recommended Adapters, Sync Solutions & Transcoders

---

🛠️ Example Types:

🔌 3.5mm AUX In-Line Isolator
Used when you run 3.5mm male-to-male cables between devices.

🔌 RCA In-Line Isolator
Used when your cable terminates in 2x RCA.

---

💡 Tip: If you hear hum or buzzing through your CRT, amplifier, or speakers, adding one of these in-line with your audio cable will usually solve it — no impact on your video signal.

---

A ferrite core, often seen as a clip-on cylinder on power or signal cables, is a passive electronic component used to suppress high-frequency electromagnetic interference (EMI) and radio frequency interference (RFI).

How it works:

• Ferrite cores act as a filter by adding a small amount of inductance to the cable, blocking unwanted high-frequency noise while allowing the desired low-frequency signals (like DC power or analog video) to pass through unaffected.
• They help reduce interference both emitted by the cable (which might radiate noise into nearby devices) and picked up by the cable (which might inject noise into your equipment).

Where you’ll find them:

• Commonly clipped onto power cables, USB cables, video cables (like VGA or DVI-I), and audio cables.
• Especially important in setups with sensitive analog signals — like CRT displays — where EMI can cause visible screen artifacts, audio hum, or signal dropouts.

---

💡 Tip: If you’re experiencing strange video noise or buzzing audio, adding or repositioning ferrite cores on your cables can sometimes help reduce the issue.

---

🛠️ Example Type:

🔌 Clip-On Ferrite Core

• ➡️ Analog to Digital (DAC)
• ➡️ Recommended Adapters, Sync Solutions & Transcoders