Recently I bought a new 5:4 BenQ BL702A TN LED monitor that has a rumor to support the 15KHz native Amiga horizontal frequency. Before that I bought a 24″ IPS WideScreen Philips that also supported 15KHz but since Im not a big fan of black border I sold it to a friend instead.

When I did my previous tests I used a 23 to 15 (Amiga RGB to VGA) D-Sub converter between the A1200 and the monitor. To be able to skip one extra connection/joint I decided to do my own 23-15 D-Sub cable.

There are many schematics out there but after some research I made the following one.




Connection Scheme

23 Pin D-Sub Description 15 Pin D-Sub
3 Red Video 1
4 Green Video 2
5 Blu Video 3
16 Red Return (GND) 6
17 Green Return (GND) 7
18 Blue Return (GND) 8
11 Horizontal Sync 13
12 Vertical Sync 14


The result was very good. Minor distortions caused by the previous adapter was completely gone and now I have a cable that I can use directly. The review of the BenQ monitor will be done later when I have found a proper cam that can record with high quality.



15 thoughts on “RGB to VGA

  1. Hi!

    I tried your schematic and was able to see some output on my Dell U2410! (but suddenly not in a good quality -> works only partly with PAL Hi Res (not laced)!

    Any ideas?!


    • Odd, has it worked before and is the Dell U2410 100% 15Khz compatible? Some monitors also requires buffering which this cable does not have.

  2. Tried this on a DELL 2001FP (Sep 2005) Did not work. Same with a Dell 2007FPb (Jan 2007). Thanks for sharing the schematic. I’m still on a quest to find a monitor that’ll work with the cable.

    • That is odd, I’ve got reports that it should work with Dell 2001FP, but do not know exact manufacture date. Perhaps those screens need a buffered adapter/cable?

  3. Hi, a question. What should the cable diagram look like? As if the vga and db23 connectors are facing, giving the face that connects to the monitor and the friend? or as if the connectors show the back where the cable welds are made ?. Thanks greetings

    • I usually just read on the connector which pin to solder. Otherwise, I would say that the DB23 is correct seen from the back and the VGA is seen from the front in the picture. Correct me if I am wrong, but the a D-Sub seen from the front mostly have the numbering from left to right, and seen from the back it is from right to left.

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