HCOM to SND Converter

Encode Macintosh HCOM audio as MS-DOS SND format

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Mac to DOS Audio

Bridge classic Macintosh HCOM audio to MS-DOS SND — connecting two major computing platforms from the early personal computer era.

Server-Side Processing

The conversion runs on our servers. No legacy software or emulators needed on your end.

Privacy Guaranteed

Your HCOM files are erased after processing. SND results are cleaned from servers within 24 hours.

How to convert HCOM to SND

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose snd or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your snd file right afterwards

About formats

HCOM is a Huffman-coded audio format from the early Macintosh era, designed to shrink digitized sound for distribution on floppy disks and bulletin board systems when storage was precious and modems were slow. The encoder takes 8-bit unsigned PCM input, computes a frequency table of sample-delta values, and builds an optimal Huffman tree that replaces common deltas with short bit sequences. Compression ratios of 2:1 or better were typical for speech recordings, a meaningful saving when a 3.5-inch floppy held only 800 KB. Files were distributed as Macintosh resource forks and played through utilities like SoundApp and the BinHex ecosystem that defined Mac software exchange in the late 1980s. The format supported sample rates up to 22.255 kHz, matching the output capabilities of original Macintosh sound hardware. Tools such as SoX retain HCOM decoding support, ensuring that archived recordings remain accessible decades later. HCOM holds three practical advantages for preservation work: lossless compression that recovers the original samples exactly, a self-contained Huffman table embedded in each file for dependency-free decoding, and historical prevalence across thousands of vintage Mac sound archives.
Developer: Apple Computer
Initial release: 1985
SND is a multi-platform audio file extension used across several computing ecosystems since the late 1980s. On Sun and NeXT workstations, .snd files follow the AU format structure — a header with magic number 0x2e736e64, data offset, encoding type, sample rate, and channel count, followed by raw audio. On MS-DOS PCs, the same .snd extension was used by early sound utilities like Sounder and SoundTool for simple 8-bit unsigned PCM recordings. Macintosh systems also employed .snd for sound resources embedded in the resource fork. Because the extension is shared across incompatible formats, audio processing tools typically inspect the file header to determine which variant they are handling: files beginning with the AU magic number are treated as Sun/NeXT audio, while headerless files are interpreted as raw PCM with assumed parameters. The Sun/NeXT variant supports multiple encodings including mu-law, A-law, 8-bit and 16-bit linear PCM, and ADPCM, making it versatile for both speech and general audio. One advantage of the AU-style SND is its self-describing header, which enables any compliant player to determine sample format and rate without external metadata. The MS-DOS SND variants hold historical value as artifacts of the era when Sound Blaster cards first brought digital audio to personal computers. SND files from all platforms can be processed and converted using SoX and other audio tools.
Initial release: 1988

Frequently Asked Questions

What is SND?

SND is an early MS-DOS audio format from the 1990s. It stores simple PCM audio data and was common in early PC applications.

Why convert HCOM to SND?

Useful for retro computing projects that need DOS-era audio. The conversion bridges classic Mac and early PC audio platforms.

What opens SND files?

SOX processes SND files. Various retro computing tools and DOS emulators can also work with this format.

Is SND still used?

SND is a historical format. It is primarily relevant for DOS-era software preservation and vintage computing enthusiasts.

Is the conversion secure?

HCOM uploads are removed right after conversion. SND outputs are deleted from our servers within 24 hours.