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.



13 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?

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