VDMSound allows the user to provide custom mappings for MIDI instruments as well as for joystick buttons and axes.
MIDI mappings are particularly useful when the type of MIDI device supported by a game is different from the type of hardware or software device actually present on the system
Joystick mappings are needed principally for DOS-based flight simulation applications, when matching yokes, throttles and pedals to the simulator's expected configuration.
As of version 2.1.0 beta, VDMSound also includes a Wizard graphical user interface, accessible by right-clicking on any MS-DOS executable.
Design
As opposed to DOSBox, which emulates an entire x86personal computer with DOS, VDMSound emulates only the sound hardware. All other aspects of DOS emulation are managed natively by the Windows operating system's 16-bit subsystem through virtualization. This results in reduced system load, at the expense of reduced compatibility
Limitations
The Windows operating system's 16-bit subsystem is lacking in several areas which directly or indirectly affect VDMSound emulation:
Incomplete DPMI support in Windows NT/2000/XP results in a number of games not starting or crashing randomly when they communicate with the emulated sound card
Improper interrupt emulation in Windows NT/2000 results in some games hanging when they communicate with the emulated sound card
Improper PIC emulation in Windows results in games not being able to use normal mode, limiting VDMSound's MPU-401 emulation support to UART-mode only.
DOSBox does not rely on the Windows 16-bit subsystem and is thus not subject to these limitations.
History
VDMSound started as a private project in 1998, in Montreal, its motivating purpose being that of capturing in-game MIDI music through software while taking advantage of Windows NT's 16-bit subsystem virtualization. It became open-source and moved to SourceForge after a full rewrite in the early spring of 2001. It was discontinued in early 2004, when additional improvements in emulation were no longer possible due to limitations in the Windows 16-bit subsystem. The sound emulation code from VDMSound has since been integrated into DOSBox. VDMSound is not compatible with Windows Vista, making the project obsolete. The current version, 2.1.0 beta, will remain the final version.
