Tom Thompson
At Boston MacWorld Expo this August, Apple is expected to introduce a new line of Power Macs ranging from a high-end system for multimedia authors to inexpensive models.
The Power Mac 8500 targets multimedia authors by offering a fast 120-MHz PowerPC 604 processor and an impressive array of integrated AV (audio-video) features. A 100-MHz PowerPC 601 powers the Power Mac 7500, and its AV features make it useful for the small- and medium-size businesses and the home office. The SOHO (small office/home office) market gets power at a low price with the 601-based Power Mac 7200 series (available in 75-MHz and 90-MHz configurations), with prices starting around $1500.
All of these Macs offer three PCI slots, two Ethernet connectors (10Base-T and AUI), and quad-speed CD-ROM drives as standard. They
use the same dynamic recompilation emulator and performance-tuned hardware architecture found in the Power Mac 9500 (see "Apple's Tsunami: PCI Power," July BYTE, page 26). The 8500 and 7500 use a plug-in processor board that allows upgrades to a faster 150-MHz PowerPC 604 chip.
The 8500 and 7500's built-in, second-generation AV capabilities are an improvement over the AV functions first introduced in the Quadra 840AV. They have 16-bit, CD-quality (44.1-kHz sample rate) stereo sound. Several ASICs enable the 8500 to capture and process live NTSC-, PAL-, and SECAM-formatted video at 8-, 16-, or 24-bit depths (the original design was limited to 8 or 16 bits). Thanks to the descriptor-based DMA, these systems can capture the video stream as a 320- by 240-pixel image at 30 frames per second, and 640- by 480-pixel image capture is supported at lower frame rates. For output, the 8500 and 7500 can display 8-, 16-, or 24-bit video in NTSC or PAL formats.
The original AV design used a split frame buffer t
hat mixed the computer and captured video inside the DAC (D/A converter) display circuitry and thus limited the screen's output to the bit depth of the captured video (8 or 16 bits). In contrast, the 8500 and 7500 use a unified frame buffer in which the signals are combined digitally, eliminating many of the restrictions found in the old design. The captured video can be a different pixel depth from the computer video, and 8-, 16-, and 24-bit depths are supported. Due to the digital signal handling, convolution algorithms can be applied at all screen depths to reduce flicker, and the video stream can be directed toward a second monitor. A DAV (Digital Audio-Video) slot lets you plug in an MPEG or other card for hardware video compression or accelerated playback. These wouldn't be decent multimedia systems without plug-and-play setup, and to this end the computers have connectors for Super-VHS video in/out, composite video in/out, and stereo sound in/out.
A Power Mac 8500 with 16 MB of RAM, 1-GB hard dr
ive, and quad-speed CD-ROM drive will sell for around $3999. A 7500 with 8 MB of RAM, 500-MB hard drive, and quad-speed CD-ROM will start around $2499. Prices for the 7200 series, with 8 MB of RAM, a 500-MB hard drive, and quad-speed CD-ROM drive will start at about $1499.
Apple's Multimedia Macs
