Full source code for Impulse Tracker, including sound drivers, network drivers, and some supporting documentation
To build Impulse Tracker, you will need:
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Turbo Assembler v4.1
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Turbo Link v3.01
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Borland MAKE v4.0
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A DOS environment
Once you have these, building IT.EXE should be just a single call to MAKE
Sound drivers are build individually via M*.BAT files inside the SoundDrivers subdirectory
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IT.ASM: Startup routines
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IT_DISK.ASM: Disk IO Routines. Uses IT_D_*.INC files
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IT_DISPL.ASM: Display routines for the Playback Screen (F5)
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IT_EMS.ASM: EMS memory handling routines
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IT_F.ASM: Collection of functions used by the object model
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IT_FOUR.ASM: Fast Fourier routines. Used by the graphic equalizer (Alt-F12). Not available on all all sound cards
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IT_G.ASM: Global key handler functions
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IT_H.ASM: Help Module (F1)
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IT_I.ASM: Sample list (F3) and Instrument list (F4) module
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IT_K.ASM: Keyboard module
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IT_L.ASM: Information line code
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IT_M.ASM: Main message loop/dispatcher
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IT_MDATA.ASM: Global music variable data
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IT_MMTSR.ASM: Sample compression/decompression routines
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IT_MOUSE.ASM: Mouse handling code
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IT_MSG.ASM: Message editor module (Shift-F9)
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IT_MUSIC.ASM: Module playback code. Also uses IT_M_EFF.INC
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IT_NET.ASM: Network code
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IT_OBJ1.ASM: UI object definitions
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IT_PE.ASM: Pattern Editor module (F2)
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IT_S.ASM: Screen functions, including character generation
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IT_TUTE.ASM: Interactive Tutorial module
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IT_VESA.ASM: VESA code for graphic equalizer
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SWITCH.INC: High level switches for the program
Q: "What are all those funny characters in the source code?"
A: I wrote the original source code using DOS characters, with characters drawing borders/boxes in comments in the source code. In the interests of posterity, I have left the code intact as it was.
Q: "Why didn't you use STRUCs or ENUMs" in your ASM source?
A: Simply because I didn't know about them at the time. I wish I did. There's a InternalDocumentation folder that I've included in the repository that details what some of the magic numbers appearing through the code might mean.
Q: "Flow in some functions seems to jump all over the place. Why?"
A: The original code was compatible all the way back to an 8086 machine. 8086 would allow you to do conditional jumps only within +/-128 bytes, so I spent too much time shuffling code around to meet this restriction. When I shifted away from this 8086 restriction, I never went back to update the code that was mutilated by it.
BSD 3-clause license can be found in LICENSE.