VGM File Info Scanner for CP/M
===============================

A utility that scans all .VGM files in the current directory and
displays a table showing which audio chips each file uses.

Version 1.1 uses a hybrid detection approach:
- Checks VGM header clock values to detect chip types
- Scans VGM command stream to detect multiple instances of same chip type

Usage:
------

Simply run the program from a directory containing VGM files:

    VGMINFO

No command line arguments are needed. The program will automatically scan
all .VGM files in the current directory.

Output:
-------

The program displays a formatted table with two columns:
  - Filename: The name of the VGM file
  - Chips Used: A comma-separated list of audio chips used in that file

Supported Chips:
----------------

The program can detect the following audio chips:
  - SN76489 (PSG - Programmable Sound Generator)
  - YM2612 (FM Synthesis chip used in Sega Genesis/Mega Drive)
  - YM2151 (OPM - FM Operator Type-M)
  - YM3812 (OPL2 - FM synthesis chip)
  - YMF262 (OPL3 - Enhanced FM synthesis chip)
  - AY-3-8910 (PSG used in many arcade and home computers)

Example Output:
---------------

VGM Music Chip Scanner v1.1

Filename  Chips Used
========  =====================
BGM       2xAY-3-8910
ENDING    AY-3-8910
INCHINA   YM2612
SHIRAKAW  SN76489, YM2612
STARTDEM  2xSN76489, AY-3-8910
WONDER01  2xSN76489
========  =====================

Notes:
------

- The program reads the VGM file headers and scans up to 255 commands from
  the VGM data stream for accurate chip detection.
  
- Files that don't have a valid VGM header are silently skipped.

- Chip detection uses a hybrid approach:
  * VGM header clock values (offsets 0x0C, 0x2C, 0x30, 0x74) determine
    which chip types are present
  * Command stream scanning detects multiple instances (e.g., "2xSN76489")

- AY-3-8910 clock detection respects VGM version - only checked for v1.51+
  to avoid false positives from invalid header data in older VGM versions.

Building:
---------

To rebuild from source:

    build_vgminfo.cmd

Or manually with TASM:

    tasm -t80 -b -g3 -fFF vgminfo.asm vgminfo.com

Author:
-------

Created for RomWBW/CP/M systems
Based on VGM format specification from vgmrips.net

An AI LLM was utilized in the creation of this
application.