The Macintosh Display Card 8•24 (sometimes called the Macintosh Display Card 670) is a 12″ NuBus video card compatible with most 680×0-based NuBus Macs, with the exception of the Centris and Quadra 660AV models. It was introduced in March 1990.
The 8•24 is an unaccelerated card, but it supports NuBus slave block transfers, so it will benefit from the installation of an 8•24 GC card as a second display card. The 8•24 supports standard Mac resolutions from 512 x 384 to 1024 x 768 in 24-bit colour (16 million colors) and 1152 x 870 in 8-bit color (256 colors). The Macintosh Portrait Display and Two-Page Display are supported in 8-bit grayscale.
There is no support for 16-bit color.
The 8•24 video card does not support resolution switching on the fly and requires a video adapter to support different resolutions on a multiscan display.
Revision B cards add support for 832 x 624, which the original card did not support.
The Display Card 8•24 requires System 6.0.5 or newer and 32-bit QuickDraw or the 32-bit QuickDraw Patch File.
This Mac video card can support a special resolution of 704 x 512, and then only on certain Apple 640 x 480 displays and with the shareware MaxAppleZoom control panel – although the control panel has apparently expired. (It was last updated in June 1993.) I have seen one recommendation for using 672-pixel mode with the 12″ Macintosh Monochrome Display.
- While unaccelerated, this card is a useful addition to a system for supporting a second monitor, particularly if an 8•24 GC card is installed. eBay has these cards fairly regularly.
- Macintosh Display Cards Overview, 1 of 3, 2 of 3, 3 of 3, Apple TIL
- Display Card 8•24 & 8•24 GC: Identifying Rev & Upgrade ROM, Apple TIL
- Macintosh Display Cards 8•24 & 8•24 GC: Rev A/B Differences, Apple TIL