IIGS video question

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There isn't a whole lot that has to be done to hook a IIGS up to a VGA monitor, not like the serious mods required to hook up my C128 to a VGA monitor. But what it boils down to is soldering a jumper from pin 3 to 15 on the bottom of the logic board. I can't solder like I used to, my hands shake too much lately, so I got some solderless breakout plugs one HD15 VGA, and one DB15. Instead of jumpering the logicboard, I can accomplish the same thing externally can't I? Pin three on the DB15 to the 15 on the HD15? I have the upscaler that will convert the 15hz signal from the IIgs to the LCD I'm going to use, but the input is HD15.

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Charles C. Faust

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Re: IIGS video question

Hi cfaust,

Take a look at this thread.
You will have the answer Smile

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Antony
Apple II forever

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Re: IIGS video question

amauget wrote:

Hi cfaust,

Take a look at this thread.
You will have the answer Smile

Hmm, this link/thread, if I were to purchase separate GBS video boards, I could in essence just build LCD monitors for individual computers with 15hz video signals. The C128 requires diodes, resisters and some round about methods to get from the RGBI signal to VGA. This will be the easiest up conversion for me so far.

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Charles C. Faust

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Re: IIGS video question

This thread will also help you:

http://www.applefritter.com/content/mono-output-only

Koichi is currently sold out on his iigs ROM3 adapters but just wait a bit and he will probably make them in the near future:

http://tulip-house.ddo.jp/DIGITAL/english.html

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Re: IIGS video question

Did the jumper from 3 to 15 on the logicboard, hooked up the adapter, VGA cable to GBS-8200 then GBS-8200 to an LCD w/VGA in. It is trying to work, but its like the horizontal sync isn't working.

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Charles C. Faust

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Re: IIGS video question
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Re: IIGS video question

You do realize the display has to support 15kHz for this to work? Almost all VGA displays do not support this, as they are all 31kHz....

You have to have a scan doubler.

I'm not sure why that site says you can just hook it up without mentioning that.

EDIT: Nevermind, I see you have some sort of device for that. Smile

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Re: IIGS video question

I read that over and over before I even attempted to do this, I get a garbled screen; I know the converter actually works because I connected the composite to the card and got the signal out as if it were hooked up to a television. I'm using a 5VDC adapter, with 2.5 amps, I thought it might have been my previous attempt with a 12VDC (the board accepts 5-12VDC), but it was only 1 amp. I read somewhere else for a different computer that you need at the bare minimum 2 amps for the board.

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Charles C. Faust

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Re: IIGS video question

Well, I have that special adapter that I got on Ebay:

http://www.ebay.com/itm/Apple-IIGS-Video-Adapter-for-the-GBS-8200-8220-Video-Converter-/131636877608?

It works 100% for me.

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Re: IIGS video question

cfaust wrote:

Did the jumper from 3 to 15 on the logicboard, hooked up the adapter, VGA cable to GBS-8200 then GBS-8200 to an LCD w/VGA in. It is trying to work, but its like the horizontal sync isn't working.

Did you press auto on the GBS-8200 to sync ? There may also be an auto-sync button on your display also. What I have is DB15 male to DB15 female hand wired thru and jumpered pins 3 to 15 so I didn't have to solder jumper on motherboard. Then a DB15 to vga adaptor plug for a Mac then vga to GBS-8200 then to LCD display. Works good.

Larry

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Re: IIGS video question

Who made (what branding) does the GBS board have? I had a faulty "Sainsmart" but got a good one from "Andoer".

If you have a device that offers component (Ý/Pb/Pr) out like a DVD player, try running that in to the GBS instead of the Apple.

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Re: IIGS video question

I hooked up the composite out to the Y input and got video just like it was on the little portable DVD player/Monitor I've been using. When I hook up through the VGA in though, I get garbled or nothing.

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Charles C. Faust

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Re: IIGS video question

The computational load for "composite in" may be less than "component in" or VGA in. That's what the GBS card is doing - a mathematical manipulation of various input signals. One mode may work, one may not. We don't know for sure.

My fear is that you spend a great deal of time thinking the card is good, when there may be some unseen issue.

I too suffered from garbled image like you describe. I was not able to test the simple "composite in" method, but perhaps I can with my suspect bad card to see if I have similar performance.

Here's how I look at it:

Composite In -> VGA Out (Good)
Component In -> VGA Out (Unknown)
VGA In -> VGA Out (Bad)

There are a couple of outstanding questions: Retrogear was asking if you had verified both an autosync on the card and the monitor. My earlier question is what was your source for the GBS card? I'm personally not a fan of Sainsmart cards based on my experience as that is the one I'm considering faulty.

One other question: What output mode are you set to on the card? 640x480? 800x600?