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-   -   Amiga RGB to S-Video + composite adaptor (https://eab.abime.net/showthread.php?t=30752)

Angus 18 September 2007 12:43

Quote:

Originally Posted by Zetr0 (Post 358652)
@Narmi

:) thanks for the heads up my friend, I was just being cautious.... since i haven`t tested it yet... :)


I hope when you do, you don't hear that sound from Impossible Mission of the little robots zapping the main character with electricity. ;)

Zetr0 18 September 2007 12:48

@Angus

LOL, that indeed is a sound that will haunt me for some time!!! and the heavy footed steps! clack clack clack clack..... its not wonder every room was setup and ready for the hero.... they could here him running before he got into the lift!!!

keropi 18 September 2007 12:51

recently it has come to my attention, that some technician here, used an EGA->VGA converter to display the aga output from a stock A1200 to a VGA monitor... although I did not see it in action, I did saw the board, it has a vga-out and an ega-in , and some chips and some adjustment screws. the friend that had the a1200 there, told me they managed to get it working and saw 3.1 on a vga monitor! I have no reason to doubt them... I will try to find a pic of that converter...
edit: I think it was a CGA to VGA converter...

edit2: yep, here it is: http://www.alibaba.com/catalog/11462...Converter.html

http://img.alibaba.com/photo/1146252..._Converter.jpg

Zetr0 18 September 2007 12:59

Thats an interesting find there Keropi-stah!

*(off to lookie at linkie)*

keropi 18 September 2007 13:03

maybe Alexh can tell us if it is of any use...

Angus 18 September 2007 13:07

As an aside, when I last used my 1200's RGB output, I reached the conclusion that the Reds were much weaker than they should be. The Blues and Grens seemed fine. Is this something I can fix (or get fixed) or is it just a worn out motherboard issue?

Thanks.

Zetr0 18 September 2007 13:12

@keropi

hmmm i have just dropped an email asking if or how it handles interlaced screens

@Angus

Thats something i havent noticed on my sir..... is it quite a difference ? if so then there may be some trouble...

keropi 18 September 2007 13:15

here is an eBay auction with 40 of them, costing ~110$ each.... the description is ancouraging!
there are high-res picks there too...

Genghiz 18 September 2007 13:27

This auction looks even closer to the current project design http://cgi.ebay.com/eBayISAPI.dll?Vi...m=150159512792 doncha think?

keropi 18 September 2007 13:34

indeed...

Zetr0 18 September 2007 13:50

indeedy indeed :)

kinda went round the houses though when you look at it.... two crystals (one pal and one ntsc) why 12vdc input, thats interesting... for end result it seems what it is doing... is a bit over complex...

but still interesting indeed...

alexh 18 September 2007 14:38

1) CGA is TTL level digital (0 to 3-5v) Amiga output is Analog (0.7v p-p)
2) CGA is 4-bit, 16-colour AGA is 24-bit, 262,144-colour

http://en.wikipedia.org/wiki/Color_Graphics_Adapter

It aint going to work.

Zetr0 18 September 2007 14:44

Quote:

Originally Posted by keropi (Post 358665)
maybe Alexh can tell us if it is of any use...

see you mention his name... and like a super Alexh soaring throught the board... he will appear :D (with small added fan fare)


@Alexh

I couldn`t read much off those chips to be honest so they could be almost anything all i could make out was the 5v regulator... maybe i need new glasses... hrmmm. theres enough caps on the board to make 3 of the above boards i rekon LOL...

alexh 18 September 2007 14:47

I've just re-read the spec of these things. They are NOT CGA-VGA converters. They are traditional 15KHz analog video scandoublers / deinterlacers.

They are also only 16-bit input.

Plus they sell for $40 elsewhere.

This is an Averlogic AL875 and an Averlogic AL250

@Genghiz
That is a video encoder, it goes from RGB to Composite / Svideo and so YES it does more fit the title of this post. Damn expensive though.

Zetr0 18 September 2007 15:02

@Alexh

that wiki link brought back some memories.....

colour artifacing.... i did this when i was 11 on the spectrum 48k....... i manage to obtain 128 distinctly different colours on screen.... .... man... a long time ago.....

narmi 18 September 2007 17:19

Quote:

Originally Posted by alexh (Post 358701)
1) CGA is TTL level digital (0 to 3-5v) Amiga output is Analog (0.7v p-p)
2) CGA is 4-bit, 16-colour AGA is 24-bit, 262,144-colour

http://en.wikipedia.org/wiki/Color_Graphics_Adapter

It aint going to work.

The Amiga has digital outputs as well, the RGBI outputs are on pins 7, 8, 9, & 6 of the 23-pin connector. The Amiga Hardware Reference Manual doesn't say what the voltage levels are, but it does say that you can only get 15 or 16 different colours depending on the monitor you use. Not worth it, IMHO.

alexh 18 September 2007 18:10

@Narmi
You didnt read my next post. These are not CGA -> VGA adapters afterall.

hurtz 18 September 2007 19:32

Quote:

Originally Posted by narmi (Post 349500)
@Zetro

I'm not planning on making any more boards, but if there is enough interest, I would like to have some boards professionally made by Futurlec.

For a run of 10 boards, the cost per board is $3. Parts would be around $15, so with postage I figure about $20 for a kit (roughly £10).

I am expressing interest! Need one for my A500, NTSC.

Thanks.

mrodfr 18 September 2007 19:58

@Zetr0 and @narmi

thanks for the technical informations.

I post some questions about for all to know the range of possibility, the advantage and all related things interesting to know about this great hardware.

I have just seen there are svga, svideo and comp on the board :-)

sorry but the design move and with the english sometime I lost/remember don't understand some informations.

narmi external deluxe is the final name ;-) a great name, isn't it ;-)

svideo and comp used at the same time on internal PCI TV card or on a LCTV monitor and I think the comp signal is this time verry good ???

also happy to know there is no need for external power supply.

The actual questions I have is:

- The hardware could handle well the differents PAL resolution the amiga have ???? (low, hires, interlaced,...) and a wait latency when changing the wb PAL screnmode ???

- The hardware design will protect the amiga hardware is one of the compoment stop to work ???? (just no signal and no amiga dead).

sorry for my questions :-)

Zetr0 18 September 2007 21:46

@mrodfr

Hello there, lets see if i can clear up some confusion for you.
  • Will this device work on a PC monitor / LCD Monitor ?
    Unfortunatley NO, the VGA port will ONLY work for 15Khz multi-sync monitor (quite rare).

  • Will this device damage or through inaction damage the Amiga ?
    Nope, NO and Not going to damage your amiga.

  • Can i use all the ports to different display devices like pc-tv in / other monitor etc ?
    Yes you can use all three outputs to different displays with out any harm.

  • Do i need external power supply ?
    No you do not, the device only uses the existing power of the RGB port

  • Will it work with hires / low-res and interlaced screens
    Yes it will work with any *native* amiga output even upto super-hires HAM, there will not be any delay changing screen modes.

  • Will this work with a scan doubler / flicker fixer device.
    ONLY if the SD/FF device supports SVideo / 15Khz VGA or Composite inputs

I hope that little bit helps.

I like the name to so I do hope Narmi likes the name of the device, after all its mainly his design :)


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