Amiga RGB to VGA adapaters require an IC?

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Jumping Anaconda

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I was hoping to do my Amiga 1200 testing in a VGA compatible screen mode using a RGB to VGA port adapter. However, I have found my adapter, but it is in two pieces, with all the wires disconnected. I tried to look up a schematic, but everything I find seems to have an IC in place. I am not sure if there was ever an IC in my adapter, just a resister across two of the pins.

I could be mistaken, but is it possible to make one of these adapters without an ic in there? If it comes to it I will just use a normal TV and go mad with the resolution and flickeriness.

I also have my original Agmia RGB > Phillips RGB cable, and I am prowling about trying to see if I have any hardware that will fit...

EDIT: Beginners error here, I probably should have put this in the help forum. Can a mode move it for me please?

Thank you
 

jvdbossc

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the adapter

the adapter

There is some topic in for sale on here about the versions of the commodore.

It has only wires in it. Some might have some electronic, however limited.

Sorry to say, you can get the workbench screen to run, but it requires some installation of video modes first.

And then some software will not be displayed.

I would not go that route to be honest, tried myself to many times, you need a 2 monitor. Or an amiga monitor or one with a composyte, or a tv.
 

Jumping Anaconda

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Thanks for your reply jvdbossc. I was aware that you can run limited VGA compatible screen modes with the standard AGA Amiga RGB output. This is not an issue though, as I only want to run Workbench based tasks to test the machine thoroughly. I can set up the drivers on a PC through UAE and hopefully just the pre-prepared drive in to a working system. Failing that, I could just give up and use a normal TV and 15 khz RGB modes. :)
 

AndyLandy

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To be honest, sticking with a TV really is the path-of-least-resistance. The Amiga->VGA adapters I have are just wires, but they only work for me as I have a multisync monitor that can handle 15Hz screenmodes. Amiga->SCART cables are pretty easy to come by and will give you good image quality.
 

Jumping Anaconda

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Thanks for the tip AndyLandy, but I am not too worried about having one or two hiccups along the way. I only want to use the VGA screenmodes, Euro 72, or whatever it is, and I can probably still work my way around whatever that software is called for hacking monitor drivers if I can find it. Using a TV is not really an option as the interference will cause me visual problems.
 

AndyLandy

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The only issue with doing that is you won't be able to go into the Early Startup menu, or boot of any floppies that don't hold your monitor driver. Still, if you have a TV as a fallback, you might find that the productivity modes are adequate for your needs.

Of course, the holy grail here is a flicker-fixer / scandoubler, but they can be a bit pricey.
 

Jumping Anaconda

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Yes, I can leave a TV in line if i need to use those menus and to get it rolling. With any luck I can get the operating system rolling in the right screenmode in WinUAE on the PC and then just drop the drive into the Amiga. I have a hunch that my Samsung TV might scan down quite low on it's VGA port as well.

I worked in an office about five years ago that had one of those NEC multisyncs that got an Amiga Format gold ready to be dumped in a corridor. There was a young office girl that was moaning about it cluttering up the place and I remeber telling her that those screens were worth over a grand when they came out. I probably shoudl have offered to take that screen away. But then CRTs do get worn out, and I would expect that it would have been very heavily used for some time.
 

Jumping Anaconda

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Does anybody have a schematic or wiring diagram for such a connector? I can't seem to find one online.
 

Jumping Anaconda

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Thanks for the link Chain, but your system seems to use an IC. I am beginning to wonder if an IC dropped out of my adapter at some point. What does the IC actually do in this circuit?
 

imnogeek

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Here is one I found out on tinternet don't know if that is what you are looking for..

Amiga RGB -> PC VGA Hardware Hack
- "What is this?", you might think.
As the title says it's simply a hardware
hack for the serious Amiga user, letting nearly anyone connect a "standard"
PC-VGA monitor to the Amiga-computer.
- "How's it done then?", you continue! =8^)
The trick is pretty simple if you know it! When the PC-monitor "needs" a
digitally HIGH sync-signal, the Amiga actually deliver a digitally LOW sync-signal.
And the other way. So to make those two things work together you ... invert
the sync-signals. The easiest way to do this is to use an Intergrated
Circuit (IC) called 74LS08N, which contains 4 AND-gates. (If you're into
digtal circuits you might know what to do by now!!) Gate 1 has it's input's
at pin 1 and 2 and it's output at pin 3. By hardwiring pin 1 and 2, the
output is OPPOSITE (also called inverted) to the input.
Phew ... A picture explains more than 2063 bytes ... have a look at the
enclosed picture "VGA_Hack.IFF"!
- "Is it possible I'm going to brake something?"
Yes!! Let an experienced person do the soldering according to the diagram.
Most electronics will not stand the electrical shock of +5V. Note that the
author of this doc and diagram has NO responsibilities for anything that
goes wrong ... though, the hack should be pretty easy to do!
- "Should I note anything else?"
Yeppers! The adaptor described in the IFF-file states that some crossing
might be needed. A friend (A4000-owner) to the author (A1200-owner) uses HIS
original VGA-converter, but was forced to build a adaptor-cable. The cable
is used to adapt the 15 pins (RGB-output) to 9 pins (VGA-socket). It can
also be used together with the described converter. Though, WHEN USED WITH
THE CONVERTER, CROSSING IN THE ADAPTOR ISN'T NEEDED. This is already done
in the converter.
- "Are you ever going to get finished with this doc?", you hopefully ask!
This hardware hack was done by TranXeye / Nova Lythern, after trying
several other hacks. But I found this solution being the best. =B-»
And so do I hope that you people out there do ...
 

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chain

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well in my case it generetes sharp and strong enough sync ticks coz that one form piggy, err miggy was probably not enough sharp for that nixdorf bstard (its was not my monitor, i build it for my friend once)

btw 7408 is AND gate :) so "OPPOSITE (also called inverted)" is a bollock
 

Zetr0

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from what I can see the 7408N just boosts/filters the HSync and VSync signals =D
 
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