Amiga monitor lead needs adapting


Standard Member
I've been given an old Amiga 500. It has a power supply and a mouse and seems to run OK, but I can't tell for sure because it has no screen\monitor.

I have a spare 19" Phillips 109P4 CRT monitor. It has the usual VGA connector but it also has a set of alternative RGB inputs (BNC sockets), which I thought might suit the Amiga, as it apparently needs an RGB monitor.

My question: Would it be feasible to modify the Amiga monitor lead so that the output end can connect to the Phillips RGB ports? Does anyone here have any info on the pinouts and connections or any idea if it would work?

The Amiga end of its monitor cable has a 23-pin plug. The other, monitor end terminates in what looks like a regular 15-pin VGA male socket but it only has 5 pins. (Gord knows what the other 18 pins are for)

Anyway, five seems right as the Phillips has five ports, R,G,B plus HSync and VSync.

Advice would be appreciated :)
Last edited:


Standard Member
Paul, thanks for your info and link - I can't believe it might be that easy! :thumbsup:
Just had a delve into my junkbox and I've even got five BNC connectors that I can, delving deeper, I've also found a old VGA male to female lead, so I can brutalize that one instead of spoiling the Amiga lead.

I know this is a REAL dumb question, but I'll ask it anyway: I assume that the monitor will only handle one set of inputs at a time, ie, I guess I could leave the new 'Amiga' lead connected to the Phillips, provided that the Amiga console wasn't connected to the other end? And then, when I wanted to run the Amiga, I'd switch off the computer so there was no signal in the VGA lead?

Thanks again :smashin:


Active Member
Glad I could help !

You can leave both computers switched on and connected to the monitor quite happily.
The monitor will have a button/switch somewhere to select which input it it should use. You won't damage it by connecting a signal to an input that isn't being used.


Standard Member
Thanks again Paul. Actually, I phoned Phillips NZ and found an intelligent, helpful, sympatico tech (rare these days) who pointed out the location of the buttons on the front of the monitor, buttons that I must have spent years looking at without seeing:oops:

So I'm good to go as soon as I get some broken computers out of the way and get some spare time. BTW, I think I said I found a bunch of BNC connectors in my spare parts box? Well, two were obviously solderable but I couldn't see how to attach cables to the other three. Took me about two hours to figure out that they were BNC to RCA adapters! :rolleyes: So I guess I'll do the two sync lines with the solderable plugs and do the other three leads as RCA.

All five leads will be fairly light on shielding, (unless I use co-ax cable), but they'll be short (300 - 400mm) so I don't imagine there will be a problem with interference.

Again, thanks for your input :thumbsup:

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