eosflash

Cross-platform CLI for inspecting, transforming, and writing E-MU E4 / EIV / E-Synth sampler firmware (EOS). Classic and Ultra generations. Runs natively on Linux and modern Windows. Supports raw disks, legacy E-MU DOS executables, and full and partial ROMs.

Note: Use emu.tools to update E4 samplers via MIDI — no floppies required!

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Usage

Inspect a file or floppy disk

eosflash verify eos.img                # Verify/Show RAW disk image
sudo eosflash verify /dev/fd0          # (Linux)   physical floppy — requires sudo
eosflash verify a:                     # (Windows) physical floppy

Compare two sources

eosflash verify a.eos b.eos            # compare payloads of two OS binaries
sudo eosflash verify eos.img /dev/fd0  # (Linux)   RAW image vs physical floppy
eosflash verify eos.exe a:             # (Windows) DOS executable vs physical floppy

Export between formats

eosflash export os.exe --img out.img --eos out.eos  # DOS executable -> RAW image, OS binary

Write floppy disk(s)

Works with both OS and Flash Prep sources.

sudo eosflash write os.eos --drv /dev/fd0     # (Linux)   create OS disk
eosflash write os.img flashprep.img --drv a:  # (Windows) OS and Flash Prep

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Advanced ROM manipulation

The flash command splits, combines, compresses and decompresses ROM binaries.

# Combine / split IC dumps
eosflash flash low.bin high.bin --rom full.rom       # combine two IC halves -> ROM
eosflash flash full.rom --lo low.bin --hi high.bin   # split ROM -> two hi/lo halves

# Extract / reassemble payloads
eosflash flash full.rom --eos os.eos --btl boot.btl  # extract OS + bootloader from ROM
eosflash flash os.eos boot.btl --rom full.rom        # reassemble OS + bootloader -> ROM

# Compress / decompress
eosflash flash compressed.eos --eos out.eos --4mb    # decompress 2MB -> 4MB compatible
eosflash flash uncompressed.eos --eos out.eos --2mb  # compress to fit in 2MB target

What to avoid

• Don't flash Ultra OS onto a Classic - Classic (1st/2nd gen EIV/E4) uses Motorola 68020; E4 Ultra uses Coldfire MCF5206E. They are not compatible.
• Don't write a corrupted source - It won't boot on real hardware. Use --force only to investigate corrupted files.
• Don't use a 64KB bootloader with a 4MB ROM target - The 4MB FlashROM has a different RAM map and IC layout; a 64 KB bootloader will not boot.

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Bugs / support

Floppy drive issues (bad sectors, mechanical failures) are normal, use freshly formatted disks before writing OS.

For everything else: open an issue here on GitHub or ping @nkrypth on the Madlabz Discord: madlabz.info