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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: jltursan on November 08, 2017, 03:36:57 PM
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Looking for a way to use my A4000's RTG Merlin card with only a monitor I have been experimenting with these cheapo Composite/S-Video to VGA converters that can be found in eBay everywhere.
The Merlin card only needs to be feeded through its "VGA in" port with a signal also in 31Khz so at first glance, it could be the right task for this kind of converter.
The A4000 doesn't have a native composite output; but let's add an old faithful Commodore A520 (http://amiga.resource.cx/exp/a520):
(http://i.imgur.com/g0w3SFGm.jpg) (https://imgur.com/g0w3SFG)
(http://i.imgur.com/c5NOqBJm.jpg) (https://imgur.com/c5NOqBJ)
Well, it works; but as expected, the quality is generally speaking, very bad. Highres laced mode can be barely used; but the Super HRL is a no go, nothing can be read.
Games can be played; but we can get some more quality from this device...
Let's try with the S-Video input...of course first we need to mod the A520 to output that kind of signal. This page (http://members.iinet.net.au/~davem2/overclock/A520.html) explains how to achieve this using a PAL model (sadly, the same author points up that he hasn't been able to mod the same a NTSC one).
This is the result:
(http://i.imgur.com/fwaUrPKm.jpg) (https://imgur.com/fwaUrPK)
Be warned that step 10 has a little confusing error, the correct resistor value is 270Ohm, not 470Ohm!.
The video quality improvement is incredible:
(http://i.imgur.com/t8s8RUqm.jpg) (https://imgur.com/t8s8RUq)
(http://i.imgur.com/Wf9o6rkm.jpg) (https://imgur.com/Wf9o6rk)
Both modes can be used without problem.
Apps and games look great. Maybe the brightness (luminance) can be lowered a bit, I haven't tested with another monitor tho...
(http://i.imgur.com/j4vCS6cm.jpg) (https://imgur.com/j4vCS6c)
(http://i.imgur.com/d2dXjbRm.jpg) (https://imgur.com/d2dXjbR) (http://i.imgur.com/iMl2w2Nm.jpg) (https://imgur.com/iMl2w2N)
(http://i.imgur.com/lb5dpAJm.jpg) (https://imgur.com/lb5dpAJ) (http://i.imgur.com/agUj2FAm.jpg) (https://imgur.com/agUj2FA)
The Merlin setup ends being something like that:
(http://i.imgur.com/W5tdkZmm.jpg) (https://imgur.com/W5tdkZm)
That's what I call a cluttered desktop :rolleyes:
If you have any other PAL Amiga model, without RTG graphics and you can't afford an Indivision, maybe this poor's man setup can be of some use for you. No idea if NTSC users can benefit of a PAL A520, I guess that they'll only get a B&W image.