MAMEWorld Forums - EmuChat - Re: Space Invaders emulation

I logged that bug. Short version: Just from listening to different videos of real machines, and a couple trips to California Extreme, it would appear that when Midway licensed the game, they built their own discrete sound components instead of reproducing Taito’s. When MAME added discrete sound emulation for Space Invaders, it sounds to have been based on a Midway board. Every version that uses the discrete emulation instead of the old samples plays the Midway sounds (which themselves don’t sound exactly like real Midway machines, either).

When the game used sound samples in MAME, it used the Taito sounds, but only one sample of each sound, which is also inaccurate. As you pointed out, the sounds are not absolutely identical every time. I have no idea how the sound actually works, but the invader death sound (probably both Taito’s and Midway’s, but most obviously Taito’s) seems to start/end in different places each time you hear it.

Do you live outside the USA? Taito distributed the game everywhere else, and as with that UK version, it appears they all used the “Taito” sounds. It would also appear that most bootlegs were based on the Taito components too - the Midway sounds appear to be unique to official Midway boards.

The solution would be for someone to write additional code to emulate the discrete sound of a Taito board, and implement that emulation in all non-Midway versions in place of what is there now. There is actually a TODO comment in the 8080bw.cpp driver code saying that the Taito and Midway sound boards still need to be compared:

Code:

To Do:
-----

- Midway PCB sets
      * The discrete components, particularly for the shot sound, differ
        between Taito and Midway audio daughterboards.
        + Figure out the difference between the Taito and Midway discrete
          boards and emulate them both properly.
        + Figure out what the current discrete setup is trying to emulate.

Edited by TServo2049 (05/14/19 10:12 PM)