cleanup in the mixer detect
add switch, support, for using DSP alias port (0x22D instead of 0x22C)
add U/I to change DSP aliasing at runtime
backwards playback added (direct DSP, goldplay, and DMA). yet to do:
backwards segmented DMA.
cleanup DMA non-auto-init DSP non-auto-init playback, forwards and
backwards.
playing backwards works now
bump version number. add correction for playback time in backwards mode
taking into consideration DMA starts from end of buffer. playback stop
code now correctly stores playback position before stopping the card,
not after, which allows the function to use DMA position properly.
add cpu/dos/windows probe to init card and both BLASTER vs probe
functions. add code to signal "not recommended" if backwards DMA is
attempted from within a v86 monitor, or Windows. add flags to remember
whether or not we detected DOSBox or VirtualBox.
Add "F9" as instant-reversal key
add warning for DSP alias port enable
refuse to start playback if backwards DMA and ADPCM is enabled, or
recording and backwards DMA is enabled. both of those modes are not
implemented in this code.
reminder to self: Pentium 120MHz laptop in storage has an ESS PnP
audiodrive chipset that the PnP support code here should recognize.