RetroMIDI said:
Old software running under CMD.EXE uses midiports such as $330/$331 or
$310/#311 to output MIDI.
Problem is Vista has automatically mapped ONLY $330 to the internal
Synth.
How can I change this and map ports to external MIDI devices?
Hi Murray
For DOS apps, I think this is controlled by NTVDM.EXE.
Starting with XP, the NTVDM emulates a Sound Blaster 2.0 sound card,
complete with emulated MPU-401 at 330. The physical PC hardware doesn't
really have a MIDI port at 330. But when you run a 16-bit DOS application,
it doesn't see the "real" physical hardware; instead the DOS app sees the
emulated hardware enabled by the NTVDM.
The configuration of the emulated sound card is controlled by the BLASTER
environmental variable, just the same as on a real MS-DOS PC with a Sound
Blaster card. On XP and Vista, the variable is defined in
C:\Windows\System32\AUTOEXEC.NT; by default it is:
SET BLASTER=A220 I5 D1 P330 T
I'm not sure exactly what you'll need to change, but I suspect that tweaking
this variable in AUTOEXEC.NT will be your best shot at changing the MIDI
locations in NTVDM.
Of course this only applies to 16-bit DOS and Windows applications. The
BLASTER variable and emulated Sound Blaster card have no effect whatever on
Win32 applications. These will plug in directly to Windows' own multimedia
facilities (such as Winmm.dll). Win32 applications would connect to a MIDI
port using the Win32 Multimedia and MCI APIs, functions such as
midiconnect().
Hope it helps,
