Sound & Music

1) No sounds please

Completely silences all music and sound effects. Useful if you want to play in absolute silence or listen to your own soundtrack in the background.

2) IBM sounds (PC Speaker)

Driver: ISOUND.CVL · Engine: BuiltInSpeaker.cs

The classic 1-bit motherboard beeper. The original DOS driver manipulated the Intel 8253 Programmable Interval Timer (PIT) on I/O port 0x61.

Our engine emulates the PIT timer gate and square-wave frequency generator, outputting smoothed PCM audio at 44.1 kHz. You get the authentic nostalgic beeps and victory tunes of 1980s and early 90s PCs.

3) Tandy sounds (Tandy 1000 / IBM PCjr)

Driver: TSOUND.CVL · Engine: TandySoundSynthesizer.cs

Newly built from scratch! In the original DOS version, Tandy 1000 and PCjr systems produced rich 3-voice polyphonic music plus a noise channel using the Texas Instruments SN76496 sound chip mapped to I/O port 0xC0. In early C# translation versions, port 0xC0 was unhandled, resulting in complete silence when selecting Tandy sounds.

We engineered a cycle-accurate software emulator of the TI SN76496:

• 3 square-wave tone channels: 10-bit frequency dividers clocked by the NTSC colorburst clock (3.579545 MHz / 32).
• 1 noise channel: periodic noise and white noise generated by a 15-bit linear feedback shift register (LFSR with polynomial x¹⁵ + x¹⁴ + 1).
• Logarithmic attenuators: 16 volume levels per channel (-2 dB per step down to silence).
• Exponential smoothing filter: converts digital chip transitions into clean, warm 44.1 kHz audio without harsh aliasing.

Now the charming 3-voice harmonies of Civilization play in full authentic glory!

4) AdLib / Sound Blaster (OPL2 FM)

Driver: ASOUND.CVL · Engine: Yamaha YM3812 (OPL2) FM Synthesizer

The gold standard of PC gaming audio throughout the early 1990s. The game runs MicroProse's ASOUND.CVL driver in an emulated 8086 CPU environment, which writes FM synthesis parameters to the 9 channels and 4 operator waveforms of the Yamaha YM3812 chip.

Delivers the authentic warm brass, synth plucks, and FM percussion that defined the Golden Age of PC gaming.

5) Roland MT-32 MIDI board (Translated to General MIDI)

Driver: RSOUND.CVL · Engine: RolandToGeneralMidi.cs

In 1991, the Roland MT-32 multi-timbral sound module was top-tier luxury hardware. It utilized Linear Arithmetic (LA) synthesis, custom patch banks, and proprietary Roland System Exclusive (SysEx) messages. Modern operating systems do not have native MT-32 hardware, and streaming raw MT-32 commands directly to General MIDI instruments caused disharmonious sounds and random drum hits due to mismatched instrument maps.

To solve this, we engineered an active real-time MIDI translation engine:

• Dynamic timbre mapping: maps MT-32 preset instrument numbers to their closest General MIDI acoustic and orchestral equivalents.
• Percussion remapping & redirection: intercepts MT-32 rhythm note triggers and routes them cleanly to General MIDI Channel 10 with calibrated note offsets.
• SysEx sanitation & controller management: strips hardware-specific SysEx commands while preserving pitch bend, volume expressions, and channel pans. Emits automated "All Notes Off" commands to eliminate stuck notes.

Music is played through your OS default MIDI synthesizer (such as the Microsoft GS Wavetable Synth), producing rich cinematic renditions of every historical civilization theme.

6) Custom sound driver (Smart Auto-Detection)

The default mode when launching the game. It dynamically queries your operating system and audio subsystem, selecting the best available audio output according to priority:

Roland MT-32 (via General MIDI) → AdLib FM → PC Speaker

Guarantees optimal sound quality out of the box with zero manual configuration.

7) AdLib (Fast 486 / YM262 fix)

Drivers: ASOUND2.CVL / ASOUND3.CVL · Author: Jim McConkey (MicroProse, 1994)

Official MicroProse update combining high-speed execution patches with advanced Yamaha YM262 chip fixes:

• High-Speed 486 / Pentium Delay Patch: On fast CPUs, the original ASOUND.CVL I/O port delay loops ran too quickly, causing dropped notes. This driver incorporates calibrated cycle delays for seamless playback.
• Yamaha YM262 (OPL-3) Stereo Fix: Fixes 4-operator register and stereo initialization on Sound Blaster 16 and Pro 2 hardware.

8) General MIDI (.MID files)

Assets: 18 Standard MIDI files (located in Assets/Midi/) · Engine: GeneralMidiPlayer.cs

Direct, high-fidelity playback of authentic Standard MIDI (.MID) arrangements crafted specifically for Civilization. The full library includes all 18 original soundtrack compositions:

• opening_raw.mid – the iconic title theme from the main menu.
• evolution_raw.mid – the dawn of mankind creation sequence.
• victory_raw.mid and defeat_raw.mid – fanfare of triumph and solemn defeat.
• 14 civilization anthems: Americans, Aztecs, Babylonians, Chinese, Egyptians, English, French, Germans, Greeks, Indians, Mongols, Romans, Russians, and Zulus.

Audio is driven directly by the OS multimedia MCI sequencer, delivering crisp, pristine instrumental arrangements.