MirrorRepos
/
RomWBW
mirror of https://github.com/wwarthen/RomWBW.git
1
0
Fork 1
Code Issues Projects Releases Wiki Activity
Browse Source

vgminfo v1.1: Improved chip detection using hybrid approach 

- Fixed missing chip detection (e.g., SN76489 in SHIRAKAW.VGM)
- Fixed false positive detection (e.g., AY-3-8910 in files without it)
- Implemented hybrid detection strategy:
  * Check VGM header clock values (offsets 0x0C, 0x2C, 0x30, 0x74) to
    determine which chip types are present
  * Scan VGM command stream (up to 255 commands) to detect multiple
    instances of same chip type (e.g., '2xSN76489')
- Added VGM version check: only read AY-3-8910 clock for VGM v1.51+
  to avoid false positives from invalid data in earlier versions
- Updated documentation with new detection approach and examples
pull/635/head
jduraes 2 months ago
parent
8fa3a7442d
commit
b55d7a3f72
2 changed files with 198 additions and 5 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 120
      Source/Apps/VGM/vgminfo.asm
  2. 83
      Source/Apps/VGM/vgminfo.txt

120
Source/Apps/VGM/vgminfo.asm
View File

@ -8,7 +8,7 @@
; (c) 2025 Joao Miguel Duraes
; Licensed under the MIT License
;
; Version: 1.0 - 06-Dec-2025
; Version: 1.1 - 06-Dec-2025
;
; Assemble with:
; TASM -80 -b vgminfo.asm vgminfo.com
@ -42,7 +42,11 @@ LF .equ 0AH ; line feed
VGM_IDENT .equ 00H ; "Vgm " identifier
VGM_VERSION .equ 08H ; Version
VGM_SN76489_CLK .equ 0CH ; SN76489 clock (4 bytes, little-endian)
VGM_YM2612_CLK .equ 2CH ; YM2612 clock (4 bytes, little-endian)
VGM_YM2151_CLK .equ 30H ; YM2151 clock (4 bytes, little-endian)
VGM_DATAOFF .equ 34H ; VGM data offset (relative to 0x34)
VGM_AY8910_CLK .equ 74H ; AY-3-8910 clock (4 bytes, little-endian)
;------------------------------------------------------------------------------
; VGM Command codes (subset)
@ -232,13 +236,116 @@ PAD_DONE:
RET
;------------------------------------------------------------------------------
; Check which chips are used by scanning VGM command stream (first ~100 cmds)
; Check which chips are used: hybrid approach
; 1. Check header clocks to see which chip types are present
; 2. Scan commands to detect multiple instances of same chip type
;------------------------------------------------------------------------------
CHECK_CHIPS:
; Initialize chip flags
XOR A
LD (CHIP_FLAGS), A
LD (CHIP_TYPES), A ; Types present from header
; Check SN76489 clock (4 bytes at 0x0C)
LD HL, VGMBUF+VGM_SN76489_CLK
LD A, (HL)
INC HL
OR (HL)
INC HL
OR (HL)
INC HL
OR (HL)
JR Z, CHK_YM2612_CLK
LD A, (CHIP_TYPES)
OR 01H ; bit 0 = SN76489 present
LD (CHIP_TYPES), A
CHK_YM2612_CLK:
; Check YM2612 clock (4 bytes at 0x2C)
LD HL, VGMBUF+VGM_YM2612_CLK
LD A, (HL)
INC HL
OR (HL)
INC HL
OR (HL)
INC HL
OR (HL)
JR Z, CHK_YM2151_CLK
LD A, (CHIP_TYPES)
OR 02H ; bit 1 = YM2612 present
LD (CHIP_TYPES), A
CHK_YM2151_CLK:
; Check YM2151 clock (4 bytes at 0x30)
LD HL, VGMBUF+VGM_YM2151_CLK
LD A, (HL)
INC HL
OR (HL)
INC HL
OR (HL)
INC HL
OR (HL)
JR Z, CHK_AY_CLK
LD A, (CHIP_TYPES)
OR 04H ; bit 2 = YM2151 present
LD (CHIP_TYPES), A
CHK_AY_CLK:
; Check AY-3-8910 clock (4 bytes at 0x74, only valid in VGM v1.51+)
LD HL, VGMBUF+VGM_VERSION
LD A, (HL) ; Get low byte of version
CP 51H ; Check if >= 0x51 (v1.51)
JR C, START_CMD_SCAN ; Skip if < v1.51
INC HL
LD A, (HL) ; Get high byte
CP 01H ; Must be 0x01
JR NZ, START_CMD_SCAN ; Skip if not v1.xx
LD HL, VGMBUF+VGM_AY8910_CLK
LD A, (HL)
INC HL
OR (HL)
INC HL
OR (HL)
INC HL
OR (HL)
JR Z, START_CMD_SCAN
LD A, (CHIP_TYPES)
OR 08H ; bit 3 = AY present
LD (CHIP_TYPES), A
START_CMD_SCAN:
; If chip type is present, scan commands to detect multiples
; Set base flags from types
LD A, (CHIP_TYPES)
BIT 0, A
JR Z, NO_SN_BASE
LD A, (CHIP_FLAGS)
OR 01H ; Set SN #1
LD (CHIP_FLAGS), A
NO_SN_BASE:
LD A, (CHIP_TYPES)
BIT 1, A
JR Z, NO_YM2612_BASE
LD A, (CHIP_FLAGS)
OR 04H ; Set YM2612 #1
LD (CHIP_FLAGS), A
NO_YM2612_BASE:
LD A, (CHIP_TYPES)
BIT 2, A
JR Z, NO_YM2151_BASE
LD A, (CHIP_FLAGS)
OR 10H ; Set YM2151 #1
LD (CHIP_FLAGS), A
NO_YM2151_BASE:
LD A, (CHIP_TYPES)
BIT 3, A
JR Z, NO_AY_BASE
LD A, (CHIP_FLAGS)
OR 40H ; Set AY #1
LD (CHIP_FLAGS), A
NO_AY_BASE:
; Compute absolute data start within VGMBUF window
LD HL, (VGMBUF+VGM_DATAOFF)
@ -254,8 +361,8 @@ GOT_OFFSET: LD DE, VGMBUF+VGM_DATAOFF
SBC HL, DE ; HL = offset from VGMBUF base
ADD HL, DE ; restore HL absolute inside VGMBUF
; Scan up to 100 commands or until EOD
LD C, 100
; Scan up to 255 commands or until EOD
LD C, 255
SCAN_LOOP: LD A, (HL)
INC HL
@ -486,7 +593,7 @@ CRLF: LD A, CR
;------------------------------------------------------------------------------
MSG_HEADER: .DB CR, LF
.DB "VGM Music Chip Scanner v1.0 - 06-Dec-2025", CR, LF
.DB "VGM Music Chip Scanner v1.1 - 06-Dec-2025", CR, LF
.DB "(c)2025 Joao Miguel Duraes - MIT License", CR, LF
.DB CR, LF
.DB "Filename Chips Used", CR, LF
@ -528,6 +635,9 @@ CHIP_FLAGS: .DB 0 ; Detected chip flags
; bit2 YM2612 #1, bit3 YM2612 #2
; bit4 YM2151 #1, bit5 YM2151 #2
; bit6 AY #1, bit7 AY #2
CHIP_TYPES: .DB 0 ; Chip types present from header
; bit0 SN76489, bit1 YM2612
; bit2 YM2151, bit3 AY-3-8910
; Buffer for VGM header + first data sector (256 bytes)
VGMBUF: .FILL 512, 0

83
Source/Apps/VGM/vgminfo.txt
View File

@ -0,0 +1,83 @@
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)
- 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
Write Preview
Loading…
Cancel
Save