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davidg5678

Connecting a Macintosh iisi to a VGA monitor

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I am having trouble setting up my Mac iisi with a monitor. I do not own any compatible DB15 Apple monitors; however, I have a Dell CRT monitor with VGA.

 

I also have a few different DB15 to VGA dip-switch adapters that seem suited for this task, but I am unsure what settings to use. Do I need a specific kind of CRT to use an adapter, or are they plug and play? I have read that only specific LCD models work, but I am unsure whether this applies to CRTs.

 

I have never seen this computer work before, so I have no way of changing settings within the operating system. In theory, I have everything necessary to use the computer. I just need to configure it properly.

 

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I have a switched Mac to VGA adapter and to use it with my Quadra 631CD and a Viewsonic LCD monitor switches 1, 3 and 5 are on and the others are off.

Edited by cruff
spelling

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Macintosh IIsi wants a display that supports Sync On Green, I have a Sony Trinitron Multiscan 210ES (now dead, unfortunately) that worked with my IIsi and IIci with the VGA adapter, now I'm using my father's Apple display purchased with the IIsi in 1991.

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It's very complicated to find a LCD (or even a CRT) who accept Sync On Green. A home, i have many display, and the only way to have an image is my acquisition card.

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On 2/14/2018 at 5:27 PM, davidg5678 said:

I also have a few different DB15 to VGA dip-switch adapters that seem suited for this task, but I am unsure what settings to use. Do I need a specific kind of CRT to use an adapter, or are they plug and play? I have read that only specific LCD models work, but I am unsure whether this applies to CRTs

First things first, the IIsi has an inexcusibly HORRIBLE video subsystem. It outputs absolutely nothing remotely usable with a standard 60Hz VGA expecting display of any type and only a handful of Apple Displays to boot. Whether your Dell is multlisync or not is the overriding concern, sync on green falls where it may, usually in line with any capable multisync display's ballpark.

 

Avoid Google (now the enemy!) and practice DuckDuckGo-fu (your new non-tracking search engine best friend) to get your CRTs specs before trying anything else. [;)]

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I did a ton of troubleshooting with my monitor adapters, and I was not able to get anything to display on the screen. My Belkin adapter looks the most promising, but it is missing a plastic knob which might be necessary for use. I am unsure whether or not this makes a difference, but I have a Radius Color Pivot IIsi Video Interface Card. Does this fix the video subsystem issues? I have no clue how to use it or if I can set it up without first using the computer normally. I looked up the model number of my CRT (Dell 781s) and found this:

 

https://web.archive.org/web/20011220004743/http://docs.us.dell.com:80/docs/monitors/688en/en/spec.htm#General

 

I appreciate the help, and I really hope I can get this to work!!

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Resolution

 
Horizontal scan range 30 kHz to 85 kHz (automatic)
Vertical scan range 50 Hz to 160 Hz (automatic)
Optimal preset resolution 1024 x 768 at 85 Hz
Highest preset resolution 1600 x 1200 at 60Hz
Highest addressable resolution*

1600 x 1200 at 65 Hz

Edited by Trash80toHP_Mini

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Lost the rest of my post. It's a multisync at least for those preset resolutions. It remains to be seen if the flexibility is there for Mac resolution compatibility for syncing to oddball timings and resolutions. Have you got the Pivot Cable? If you do, install it, no drivers required, set VGA adapter to 16" and see what happens.

 

Gotta run, good luck!

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If you're getting at least 640 x 480, an extron sync stabilizer can strip sync on green and output as C sync on H, or separate H/V sync. It's also a nice device for other reasons too (H shift knob and sync handling).

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OOPSIE! Though it was your sig that listed a 6500. What other Macs have you got to do a baseline test of that CRT? The following applies to just about any other Mac you may have on hand.

 

the oopsie part:

Stop wasting time with IIsi testing, I see you've got a 6500. Use that to get the monitor up and running at 640x480 in MacHz(Don't recall offhand) and at 16" Mac Standard. If your 6500 can put those pixels on the CRT, the IIsi can as well.

 

If the 6500 can't do it, all the IIsi tinkering in the world is a lost cause.

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I have a PowerMac G4 that can probably run the screen at 640x480. I am unsure whether or not the G4 will run the screen at the same frequencies necessary for a IIsi. I will test it out today.

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I attached the CRT to my G4 Cube with VGA and was able to run the display at 640x480 60hz, but the G4 would not let me set anything lower. (I think I read something about 15hz?)

 

I took a closer look at the IIsi and realized that it does not have a boot chime. This probably means there are some capacitor issues with the computer. I would like to determine if I can even theoretically use the computer with my monitors before attempting a re-cap. (there is no noticeable damage after cleaning the board)

 

I re-read a post above where a Pivot Cable was mentioned: what is the purpose of such a cable? Can someone explain what the Pivot Card does and how to use it? -I am not sure I understand. I do not know where to continue from here.

 

Thanks for all of the help!

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If you have no boot chime start easy. I'm not a iisi expert but I would literally start with cleaning ram and any other slotted card(s) with deoxit or even alcohol and q-tips. I've revived more PCs than I can count just starting there.

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Thanks for the suggestion: I cleaned the entire computer and motherboard thoroughly with isopropyl alcohol, but unfortunately it had no effect. I need more information about the way the IIsi works with displays before continuing with recapping.

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