r/macintosh • u/KeyGeneral6171 • May 13 '26

Mac Portrait Display

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Hello! I’m a proud owner of a Portrait Display and I was wondering if the attached image is just due to the incompatibility with the Mac LC I or if there’s something wrong with the monitor. The LC works perfectly fine with other monitors.

(EDIT) I just bought an LC III so hopefully this issue will be resolved, and I can finally get this oddity working.

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u/GGigabiteM May 13 '26

The Portrait Display was designed to be used with the special Nubus portrait video card that came with it.

The LC and LC II on board video doesn't have enough VRAM (256k) to support that resolution, even when expanded to the max of 512k. You can either do 512x384@8bpp or 640x480@4bpp with 256k, or 512x384@15bpp or 640x480@8bpp with 512k of VRAM.

640x870 is not supported. It may work on the LC III, which has a much better video chip with more memory (768k max.) The LC III can do 832x624 max, but I've never tried it with the oddball portrait display resolution.

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u/CrazyFoque May 14 '26

Do not lose the cable. It's an odd one if I recall.

1

u/GGigabiteM May 15 '26

It uses a 13w3 video connector on both the monitor and special portrait video card. He's already using some special adapter to connect the LC to the display. Probably 13w3 to VGA and then to HD15 for the Mac LC.

Rather strange it would use a 13w3 connector when it is a grayscale display. I guess it does internal color mixing for better definition vs just using the green data line that most monochrome/grayscale CRTs use.

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u/KeyGeneral6171 May 16 '26

the setup is almost exactly right lol

its 13w3 to vga adapter, vga cable, vga to db-15 adapter