Running the Macintosh II High Resolution Video Card at 512x384?

[Ron's Computer Videos]

Apple's Nubus Macintosh II High Resolution Video Card for the Mac II ***supposedly*** supports 512x384 resolution. I also have a Sony CPD-200sf multisync VGA monitor. I purchased a PTC MAC to VGA Adapter on Amazon which also ***supposedly*** supports 512x384 resolution.

With the card installed in a Quadra 700, for the life of me, I cannot get the Mac to display another other than a 640x480 signal.

I've reset the PRAM multiple times to clear out the last resolution... and it makes no difference.

HELP?

Macintosh II High Resolution Video Card - Low End Mac

The Macintosh II High Resolution Video Card is a 12? NuBus card compatible with 68K- and PowerPC-based Macs running up to Mac OS 8.1. It is not compatible with the Centris/Quadra 660AV. Details The Mac II High Res Video Card is unaccelerated. It supports resolutions of 640 x 480 and 512 x 384...

lowendmac.com

Sony CPD-200sf | CRT Database

Sony's Multiscan 200sf is a very capable late '90s PC monitor. Picture is very sharp and it has an 80 kHz horizontal scan rate, allowing for 1280x1024 at 75 Hz or 1024x768 up to 98 Hz.

crtdatabase.com

Amazon.com

 

[KennyPowers]

Apple's Nubus Macintosh II High Resolution Video Card for the Mac II ***supposedly*** supports 512x384 resolution. I also have a Sony CPD-200sf multisync VGA monitor. I purchased a PTC MAC to VGA Adapter on Amazon which also ***supposedly*** supports 512x384 resolution.

With the card installed in a Quadra 700, for the life of me, I cannot get the Mac to display another other than a 640x480 signal.

I've reset the PRAM multiple times to clear out the last resolution... and it makes no difference.

HELP?

Macintosh II High Resolution Video Card - Low End Mac

The Macintosh II High Resolution Video Card is a 12? NuBus card compatible with 68K- and PowerPC-based Macs running up to Mac OS 8.1. It is not compatible with the Centris/Quadra 660AV. Details The Mac II High Res Video Card is unaccelerated. It supports resolutions of 640 x 480 and 512 x 384...

lowendmac.com

Sony CPD-200sf | CRT Database

Sony's Multiscan 200sf is a very capable late '90s PC monitor. Picture is very sharp and it has an 80 kHz horizontal scan rate, allowing for 1280x1024 at 75 Hz or 1024x768 up to 98 Hz.

crtdatabase.com

Amazon.com

How are the dip switches on the VGA adapter set? If they're set to simulate a multisync monitor, maybe try changing them to simulate a fixed-frequency 512x384 monitor and see what happens?

 

[Ron's Computer Videos]

The adapter has settings for the 12" RGB, but no matter what jumper settings I try it will always default to 640x480.

UPDATE: I tested again this morning to make sure that tired eyes weren't the issue here, and I've confirmed that none of these jumper settings will work.

 

[joevt]

I would choose 13467.
Do you have a different Mac that supports 512x384 to make sure the adapter+display works?
A Macintosh LC?
Any Power Mac with built in video or an ATI video card?

 

[Ron's Computer Videos]

Last ditch effort this morning, I hooked up an original LC (which absolutely supports 512x384) and set the jumpers to the MODE 1 settings. My Sony CRT finally produced an "OUT OF RANGE" error message. Connected the video to my Extron RGB-HDMI 300 A and I get a 512x384 image.

Reconnected the Q700 w/ the Macintosh II High Resolution Video Card, and get 640x480.

ARGH!

 

[Ron's Computer Videos]

I would choose 13467.
Do you have a different Mac that supports 512x384 to make sure the adapter+display works?
A Macintosh LC?
Any Power Mac with built in video or an ATI video card?

There's a real short list of video cards for the Mac that support 512x384. The Macintosh II High Resolution Video Card, the Macintosh Display Card 4•8, the Macintosh Display Card 8•24 and the built-in video hardware on the early "LC" Macs (since they were designed to have compatibility with that cheap 12" RGB/B&W CRT they targeted at schools). So a PPC Mac or an ATI card is likely fundamentally incompatible with what I'm testing here.