Gonbes GBS-8200 User Manual

This is a support manual for the GBS-8220 – which comes in a one vga port and two port version.
When using this board you want to read all the information in this document – there are many
common mistakes/issues when using this for arcade conversion that can easily be cleared up.
Most common is using a 1Amp power supply or wrong power. This board works best with 5V and at
least 2Amps. Less than 2 Amps will give problems!
Another common issue is Red Color increasing and video issues. Adjusting the "clamp ST" and "clamp
SP" settings of the board will usually correct this.
Other issues are incorrect signal connections.
Who makes these cards?
These are made by Gonbes.
The model numbers are GBS-8200 / GBS-8220. They mostly look the same except the 8220 has 2 VGA
D-SUB 15 connectors in output.
http://en.gonbes.com/product_detail.asp?menuid=94&id=22
What is it?
It's a pcb card for video upscaling, that can convert a 15Khz RGBS input (e.g. from a JAMMA board) or a
composite (YPbPr) signal into a more conventional 31 Khz VGA output, compatible with most modern
monitors and LCD/LED TVs (which no longer recognize 15Khz).
Commonly used to convert old consoles/computers to a VGA signal, upgranding old cabs into newer
monitors, and superguns of course.
How well does it work?
Your mileage may vary. Many people seem to be happy with it but many others have a number if issues.
Outputs 60Hz so may be worse if your input is 50Hz. (I've only tried 60 Hz)
What are the issues?
The upscaling applies a bit of smoothing, which you can reduce using a "sharpness" setting.
When in operation you may see some noise with some pixels flickering. This is barely noticeable (it's
pixels of the output resolution so they're small) and some TVs may correct it (haven't tried).
You may have sync issues if your grounding or power source is not good enough.
Does it slow down the video?
Probably but not as far as I can tell. The movement feels like 60Hz.
I can notice some interlacing in some shadows (ie. for strong black flickering on white) but it's massively
better than the FPS being put out by a Multi PCB for example (30 fps).
(update: using a scanline filter improves the interlacing by hiding some of it. still noticeable but plenty
playable)

Gonbes GBS-8200 Specifications

General

Brand	Gonbes
Model	GBS-8200
Category	Media Converter
Language	English

Summary

Product Overview and Issues

Who Makes These Cards?

Identifies Gonbes as the manufacturer and lists model numbers GBS-8200/8220.

What is the GBS-8220?

Explains its function as a video upscaler for 15Khz RGBS to 31Khz VGA output.

Common Issues and Solutions

Details common problems like power supply, color issues, and signal connections.

Video Performance and Lag

Discusses potential video smoothing, noise, and impact on perceived video speed.

User Experience and Sync Issues

Shares personal experiences with noise, sync problems, and power supply impact.

Model Differences and Authenticity

Compares GBS-8200/8220 and advises on identifying genuine products.

Power Supply Requirements

Specifies the needed power supply (5V 2A) and consequences of inadequate power.

Basic Setup and Connectivity

Included Components

Lists the items included with the GBS-8220 converter PCB.

Connecting VGA Output

Instructions for connecting monitors to the VGA OUT ports.

Connecting Video Source

Details on connecting CGA/EGA/YUV or component video sources.

RGB Cable Pinout

Specifies the pin connections for the 8-pin RGB cable.

Powering and Auto-Adjustment

Steps for powering the device and using the auto-adjust function.

Item Review and Performance

Review Description and Features

Details the converter's capabilities and supported signal types.

Value, Packaging, and Conclusion

Assesses cost-effectiveness, shipping, and provides an overall summary and score.

Installation and Configuration

Describes the ease of setup, menu navigation, and setting adjustments.

Usage and Settings Saving

Covers user experience, saving settings across power cycles, and overall satisfaction.

System Compatibility Testing

MVS and Saturn Performance

Details positive results for MVS and Saturn, noting minor shimmer issues.

PC Engine and Genesis 1 Issues

Reports sync and darkness issues with PC Engine and Genesis 1, suggesting fixes.

Game Cube and PS2 Performance

Describes good results for Game Cube and PS2, with shimmer less noticeable in 3D games.