Added Amigas and Monitors Engineering Change Request, August 31, 1993 with thanks to Ove Mejlgaard.
Contains schematics 365377-01 (video buffering with sync generation) and 365377-02 (simple video buffering) 23-pin RGB to 15-pin VGA adapters as well as PCB artwork drawings for 390682-03 23-pin to 15-pin adapter.
Warning about the eBay seller, selling the GBS in a box – the items draws more power than the specs of the Amiga recommends
So my RGB to VGA converter arrived. I’ll write up on how to connect a VGA monitor to the Amiga.
23 Pin D-SUB Female (preferable with a casing)
Solder iron + solder
5V / 2A DC adapter. These can be aquired from ebay.
Some wire if you want the item to be further from the Amiga.
And the “RGB to VGA converter” (search sentence in quotes used for ebay)
Simple solder skills are required
Click on the images below for larger pictures
GBS 8200 with RGB wire
The item as aquired. It came with 2 sets of wires. One set for power (upper right corner of the pcb) and a set for video. A 5 1/4″ floppy has been placed behind it for reference of size.
I’ve marked the 5 locations on the PCB that have interest for us.
VGA output (connect the VGA monitor to this)
5V / 2A power input. The cable that comes with the converter can be plugged into the white socket.
Menu buttons, change output resolution, adjust vertical/horizontal position etc. Change input source / auto detect input.
B, G, R signal strength. Mine is set to max for all 3.
RGB input from the amiga, using the cable shown on top of the picture.
The cable that came with my converter was properly colour coded, the RGB was proper red, green and blue, and gnd is black.
For this setup the V-Sync (yellow cable) is not needed.
23 pin connected to cable
On the picture above you can see how the cable needs to be connected to the solder side of the 23 Pin D-Sub female connector. Connect the finished wire to (5) and the amiga. Power on everything and you’re good to go.
Converted 640×256 to 1024×768
UPDATE: I made a movie for 640×512 (high-res interlaced) to show how it looks like
This converter has a menu which came in Chinese. This can be changed in the menu, step one up, and select English.
The rest of the menu speaks for itself. The settings I adjusted was Horizontal/Vertical stretch, and Positioning. Also changed from 640×480 to 1024×768 for the output resolution.
I must confess that the image output is really great compared to the price.
Update (2014-10-22): Henrik Christensen made a nice box, see below
Why make a RGB cable when you can take an old RGB one and just solder one connector? Much better solution than creating a cable from scratch isn’t it?
Word of warning: Someone is selling this packed in a nice box on ebay, I don’t agree with the high price for the box, and if you are going to get it shipped, you might as well pick up the Indivision or ScanJuggler.
EDIT: I must recommend against this as it can burn/kill your amiga. the 5V power or the 12V powerline given by the Amiga is only 100mA, whereas the GBS draws around 300-350mA @ 5V, I haven’t checked how much it draws at 12V, this I have to test ofc.
This last item -sold on eBay- draws power from the output port of the Amiga, which output current only is designed for 100mA, this item draws 3x more current than what the Amiga is designed for, therefore it can destroy your amiga if you use this. The one without a box use an external power supply and doesn’t have this problem.
I originally wrote this article for the CiA website.