DEESSE SOFTWARE

Rev. 1.0 © April 2000, Xavier Joubert

 

Deesse Xbios Interface Specifications

WARNING : this document is a draft. This should be considered a quick view of what is expected in the software support of the Déesse PCI Card.

New Xbios calls to support the 56301 DSP and all the new features of the sound sub-system (new frequencies and resolutions)

Falcon compatibility box :

This compatibility interface is expected to let all cleanly written Falcon programs run. This means that programs that access hardware directly (without using the Xbios) won't work (This would mean writing a Falcon hardware emulator using 060 PMMU).

- Emulation of all DSP and sound related Xbios calls.
- Original Falcon sound frequencies and resolutions emulation.
- Emulation of an external clock for the sound (44.1 and 48 kHz).
- DSP 56001 emulation. 2 stages emulation : analyse and patch of the DSP code before loading and on-the-fly emulation by the DSP for specific cases. Should be accurate for 95% of DSP code used on the Falcon.
- For the 5% left : DSP code library. If a code does not work, we will make a real 56301 version of it, and the Xbios will use this version instead of the original, without modification of the program. So, the final compatibility should be close to 100%.
- Falcon DMA Emulation using 56301 PCI interface and DSP interruptions.