Diamond Rio PMP300 Management Tool

Complete solution for managing the Diamond Rio PMP300 MP3 player on modern computers.

The PMP300 was one of the first portable MP3 players (1998). This project provides a CLI tool and Arduino-based USB interface to use it with modern computers that lack parallel ports.

Quick Start

Hardware Setup: Connect Arduino to PMP300 (see Wiring Guide)
Flash Firmware: pmp300 flash (requires arduino-cli)
Test: pmp300 test
Use: pmp300 list, pmp300 upload song.mp3, etc.

See QUICKSTART.md for detailed 5-minute setup guide.

What You Can Do

File Operations

Upload MP3 files to device
Download files from device
Delete individual files or all files
List files with metadata (size, timestamp)

Device Management

View device information (capacity, free space)
Change playback order of songs
Format/initialize device
Bad block detection
Switch between internal flash and external SmartMedia card

Not Supported

Firmware updates (no public protocol exists)

CLI Commands

pmp300 test                          # Test Arduino and PMP300 connection
pmp300 flash                         # Flash Arduino with firmware
pmp300 list                          # List all files
pmp300 info                          # Show device information
pmp300 upload song.mp3               # Upload file(s)
pmp300 download song.mp3             # Download file
pmp300 delete song.mp3               # Delete file(s)
pmp300 move 3 1                      # Rearrange playback order
pmp300 format                        # Format device
pmp300 storage list                  # Show available storage (internal/external)
pmp300 storage switch external       # Switch to SmartMedia card
pmp300 version                       # Show version

See CLI_README.md for complete command reference.

Hardware

Device Specifications

Model: Diamond Rio PMP300
Storage: 32MB internal flash (64MB on SE models)
Interface: Parallel Port (LPT)
Block Size: 32KB (32,768 bytes)
Total Blocks: 1024 (32MB) or 2048 (64MB SE)

Modern Interface Options

Recommended: Arduino USB Bridge

Arduino Mega 2560 or Uno
DB-25 female connector
15 signal wires + ground
Cost: ~$30-50 total

See arduino/ directory for:

Complete firmware (auto-detects Mega/Uno)
Wiring diagrams
Protocol documentation
Hardware test sketch

Parallel Port Pinout

DB-25 female connector (PC side):

Data Pins (8 signals, bidirectional):

Pins 2-9: Data 0-7

Control Pins (2 signals used, output):

Pin 16: nInitialize
Pin 17: nSelect-In

Status Pins (5 signals, input):

Pin 15: nError
Pin 13: Select
Pin 12: Paper-Out
Pin 10: nAck
Pin 11: Busy

Ground:

Pins 18-25: Ground (connect all)

See arduino/WIRING.md for complete wiring diagrams.

Protocol Overview

Communication

5V TTL logic levels
Bidirectional parallel port
Command/response protocol
Microsecond timing control

Data Organization

Block 0: Directory and FAT
Blocks 1+: File data (32KB each)
Max Files: 60
Max Filename: 127 characters

Timing (typical)

Reading directory: ~30 seconds
Uploading 1MB file: ~5 minutes
Uploading full 32MB: ~2.5 hours
Bad block scan: ~3-4 hours (32MB)

Protocol Version

Version 107 (0x6B)

Installation

Requirements

Go 1.21 or later
Arduino Mega 2560 or Uno
arduino-cli (for flashing firmware)

Build

git clone https://github.com/murdinc/pmp300
cd pmp300
make build
# Binary at: build/pmp300

Or install to system:

make install
# Installs to $GOPATH/bin/pmp300

Flash Arduino Firmware

# Install arduino-cli first
brew install arduino-cli  # macOS
# or see: https://arduino.github.io/arduino-cli/

# Flash firmware (auto-detects board and port)
pmp300 flash

Set Device

# Set once per session
export PMP300_DEVICE=/dev/cu.usbmodem14201

# Or add to ~/.zshrc or ~/.bashrc
echo 'export PMP300_DEVICE=/dev/cu.usbmodem14201' >> ~/.zshrc

Example Usage

# Test everything works
pmp300 test

# Check device info
pmp300 info

# Upload music to internal flash (default)
pmp300 upload ~/Music/*.mp3

# List files on internal flash
pmp300 list --verbose

# Check if SmartMedia card is inserted
pmp300 storage list

# Switch to external SmartMedia card
pmp300 storage switch external

# Upload to SmartMedia card
pmp300 upload ~/Music/album/*.mp3

# List files on SmartMedia
pmp300 list

# Switch back to internal
pmp300 storage switch internal

# Rearrange songs
pmp300 move 5 1    # Move track 5 to first position

# Download a file
pmp300 download "01 Song.mp3" --output ~/backup/

# Delete files
pmp300 delete old-song.mp3
pmp300 delete --all  # Delete everything

# Format device (formats current storage)
pmp300 format

Technical Details

Port Registers

Register	Offset	Access	Description
Data	+0	R/W	8-bit data
Status	+1	R	Device status (bits 3-7 used)
Control	+2	R/W	Control signals (bits 2-3 used)

Directory Structure

Header (32 bytes):

Entry count, free blocks, bad blocks, total blocks
Timestamp, checksum, version

Entries (60 × 144 bytes):

Block position, block count, total size
Timestamp (YYMMDDHHMMSS)
Filename (128 bytes, null-terminated)

FAT (8192 bytes):

One byte per block
0x00 = Used, 0x0F = Bad, 0xFF = Free

Total: 32KB (one block)

Block Operations

Reading:

Send read command (0xA0)
Send 3-byte block address
Wait for device ready
Read 32KB data

Writing:

Send write command (0xAB)
Send 3-byte block address
Write data in 512-byte chunks (64 chunks)
Send checksum per chunk
Wait for acknowledge per chunk

Project Structure

pmp300/
├── main.go              # CLI entry point
├── cmd/                 # CLI commands
├── pkg/
│   ├── arduino/         # Arduino bridge protocol
│   └── pmp300/          # PMP300 device protocol
├── arduino/             # Firmware and wiring docs
├── CLI_README.md        # Complete CLI reference
├── QUICKSTART.md        # 5-minute setup guide
└── Makefile             # Build automation

Documentation

QUICKSTART.md - Get running in 5 minutes
CLI_README.md - Complete command reference
arduino/README.md - Firmware documentation
arduino/PROTOCOL.md - Arduino bridge protocol
arduino/WIRING.md - Wiring diagrams

Troubleshooting

Device not found

# Find Arduino device
./scripts/find-device.sh
export PMP300_DEVICE=/dev/cu.usbmodem14201

Test fails

# Flash firmware first
pmp300 flash

# Check wiring
# Upload arduino/hardware_test/hardware_test.ino
# Use multimeter to verify connections

Upload/download slow

This is normal! Parallel port protocol is inherently slow:

~3.5 KB/second typical
Limited by protocol, not implementation
Original software had same speeds

Connection issues

Check all 15 signal wires are connected
Verify ground connection (critical!)
Ensure PMP300 is powered on
Try different USB cable for Arduino
Press Arduino reset button

Performance Notes

Operation	Time
Read directory	~30 seconds
Upload 1MB	~5 minutes
Upload 32MB	~2.5 hours
Download 1MB	~5 minutes
Bad block scan (32MB)	~3-4 hours

Development

Building from Source

git clone https://github.com/murdinc/pmp300
cd pmp300
make deps      # Download dependencies
make build     # Build CLI tool
make test      # Run tests

Running Development Version

go run main.go test
go run main.go list

Code Organization

cmd/ - Cobra CLI commands
pkg/arduino/ - Arduino bridge communication
pkg/pmp300/ - PMP300 protocol implementation
arduino/ - Firmware and documentation

References

License

This documentation and software are provided for educational and preservation purposes. The PMP300 protocol is based on reverse-engineered information from open-source implementations.

Note: Direct hardware access requires elevated privileges. Use caution when working with hardware interfaces.

Name		Name	Last commit message	Last commit date
Latest commit History 9 Commits
arduino		arduino
cmd		cmd
pkg/arduino		pkg/arduino
scripts		scripts
.gitignore		.gitignore
CLI_README.md		CLI_README.md
Makefile		Makefile
QUICKSTART.md		QUICKSTART.md
README.md		README.md
go.mod		go.mod
go.sum		go.sum
main.go		main.go

murdinc/pmp300

Folders and files

Latest commit

History

Repository files navigation