Impulse Tracker
Full source code for Impulse Tracker, including sound drivers, network drivers, and some supporting documentation
Pre-Requisite Software
To build Impulse Tracker, you will need:
Turbo Assembler v4.1
Turbo Link v3.01
Borland MAKE v4.0
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
Quick File Overview
IT.ASM: Startup routines
IT_DISK.ASM: Disk IO Routines. Uses IT_D_*.INC files
IT_DISPL.ASM: Display routines for the Playback Screen (F5)
IT_EMS.ASM: EMS memory handling routines
IT_F.ASM: Collection of functions used by the object model
IT_FOUR.ASM: Fast Fourier routines. Used by the graphic equalizer (Alt-F12). Not available on all all sound cards
IT_G.ASM: Global key handler functions
IT_H.ASM: Help Module (F1)
IT_I.ASM: Sample list (F3) and Instrument list (F4) module
IT_K.ASM: Keyboard module
IT_L.ASM: Information line code
IT_M.ASM: Main message loop/dispatcher
IT_MDATA.ASM: Global music variable data
IT_MMTSR.ASM: Sample compression/decompression routines
IT_MOUSE.ASM: Mouse handling code
IT_MSG.ASM: Message editor module (Shift-F9)
IT_MUSIC.ASM: Module playback code. Also uses IT_M_EFF.INC
IT_NET.ASM: Network code
IT_OBJ1.ASM: UI object definitions
IT_PE.ASM: Pattern Editor module (F2)
IT_S.ASM: Screen functions, including character generation
IT_TUTE.ASM: Interactive Tutorial module
IT_VESA.ASM: VESA code for graphic equalizer
SWITCH.INC: High level switches for the program
Frequently Asked Questions
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.
License
License for this source code is pending.