Philips SAA7785 Computer Hardware User Manual


 
ThunderBird Avenger
TM
PCI Audio SAA7785
Accelerator
Philips Semiconductors Preliminary Specification
1999 Nov 12 10
total simultaneous voices.
ActiMedia
TM
DSP Architecture
ActiMedia
TM
DSP architecture combines the strengths
of programmable and fixed function DSP architectures.
Programmability enables custom features, field
upgrades, and simple application development, while
an array of gate-efficient fixed function DSP processors
(accelerators) operate in parallel to provide an
excellent price/performance ratio. Unlike fixed-point
DSPs that must use a single resolution for all audio
processing, each accelerator is designed with the
optimum resolution for its function. This provides audio
integrity without the cost of high resolution or floating
point programmable DSP implementation.
Digital Model Dual Game Port
The software polling used by analog game ports can
consume up to 10% of the host CPU. ThunderBird PCI
products utilize a digital operation mode that can
eliminate software polling and accelerate the game
port function resulting in significantly improved system
performance. Joystick buttons can be polled or
interrupt driven to further enhance performance. A
default analog mode assures compatibility with DOS
and other non-DirectInput
TM
applications.
Comprehensive Legacy Audio Support
SoundBlaster Pro compatibility in both Real Mode DOS
and DOS windows is achieved through hardware
SoundBlaster and OPL3 (FM) emulation registers.
Legacy DMA over the PCI bus is supported on all
major platforms utilizing PC/PCI, DDMA, or Philips
proprietary Legacy Accommodation Mode
TM
(LAM
TM
).
DOS music synthesis includes stereo MIDI playback
and quad/5.1 MIDI playback as well as FM emulation.