Emax I OS 4.5

WHAT'S THE DEAL?

Give the Emax I a bar-loop workflow: play a part, let it come around, add another one. Leave REC without killing playback. Jump to the next track and keep going. Bring your own sounds; these four disks are OS-only :)

I wanted a sequence bar loop based on my emax to match the sp1200 and make a killer 12bit combo. Nearly twenty years later, I finally made it happen, with ChatGPT's honestly insane help and a whole lot of trial and error.

4.5 is our project version, not an official E-mu release number.
No samples, demo sequences, boot intro or credits screen are bundled.

PICK YOUR EDITION

These are complete 800 KB floppy images, not EPROM files or SE installers. Use the edition matching your machine's upgrades. Standard can also run on an SE with the Standard feature set; it does not permanently remove the SE upgrade. The SE/Plus images do not install that upgrade on a plain Emax. These builds are for Emax I, not Emax II.

SE is the owner-approved 4.5 SaveFix, unchanged. Standard is the approved 4.5 without intro, unchanged. HD and Plus now have the same readable 4.5 menus and defaults; they passed software checks but still need testing on matching HD/Plus hardware. Their SCSI hardware was not simulated or tested.

QUICK START

1. Put the matching .img into your usual floppy / disk-emulator workflow.
2. Boot and load or sample some sounds. The bank starts empty.
3. Default loop: 2 bars. Live quantize: ON, 1/16. Swing: 50. Count-in: 0.
4. Hit REC/PLAY and play. Recording keeps going around until you leave REC.
5. Hit REC again: recording ends, playback keeps rolling. STOP stops both.

Stop before saving so recording edits are consolidated. Keep copies of your working disks and banks. Keep the OS on working bank disks consistent with the edition you booted: Emax loads code from disk when changing modules. Use its Copy Software function when needed and read its prompts; it can clear RAM. Follow your normal image-writing procedure for your drive/emulator.

THE GOOD STUFF

SETUP 1 - STATUS

R = record, P = play, M = mute. The editing order is R -> P -> M. Put the current track into P, move across and put another track into R, all while playback keeps rolling. Choosing R during playback enters REC. An empty track picks up the current preset when armed: choose a sound first. The cursor starts on the recording target and respects your later movement.

While on Status, keys 1-8 toggle mute/play for tracks 1-8. Press again to bring a part back. These shortcuts belong to Status; 16 tracks still exist.

SETUP 7 - LOOP BARS

Pick 1-32 bars while stopped. Bars are counted in 4/4. Startup is 2 bars. The label reads "7 Loop Bars"; the editor reads "Bars:".

SETUP 8 - DUPLICATE

Double the active loop: 2 -> 4 -> 8 -> 16 -> 32. Stop first and leave some free memory for the temporary copy.

Take an 8-bar sequence, shorten it to 2, then Duplicate: you get the first 2 bars twice, for 4 total. The hidden old 6 bars are removed from the result. Silence counts too. Held notes get a stored release at the cut boundary. Changing Bars selects a window; Duplicate commits that cut to the result.

SETUP 9 - QUANTIZE

Scroll left/right through these pages while stopped:

• Q Off0 On1: live quantize OFF/ON. Startup: ON.
• Q 8/16/32: grid choice. Startup: 16.
• Swing%: 50-75. 50 is straight.
• Apply 00=ALL: 00 for every track, 01-16 for one track. ENTER does it.

Live quantize snaps recorded timing to the nearest grid at full strength. No secret loose setting. Want it bent? That's what Swing is for. You hear your live playing immediately; the stored timing is quantized. Turning Q on does not move older notes. Use Apply for those.

Apply uses the chosen Grid and Swing even when live Q is OFF. It changes existing sequence data, so keep a copy if you want the old performance. Short notes keep a minimum gate; repeated-note ordering keeps attacks tight.

MANAGE 7 - COUNT IN

Choose 0-8 bars before recording starts. Default: 0, straight in. The label reads "7 Count In"; the editor reads "Count In:".

MIDI SETTINGS: TWO DIFFERENT THINGS

Start/Stop receive is enabled for the startup preset by this OS at boot. It is a default, not a permanent lock: you can change it. Loading another bank brings that bank's preset settings, so check them after loading. MIDI clock source is a separate setting; choose external clock for slave use.

Notes/Wheels filtering is NOT forced by this OS. It follows the active preset/bank settings. Your personal filter choice is not baked into these disks. Save the relevant preset/bank settings in your normal workflow.

Each edition retains its own native MIDI receiver, UART and clock scheduler. This pack does not include the rejected MIDI-clock experiment, and Standard is not a promise of better sync. The SE MIDI code remains on the accepted 4.2.2 Loop Bar Seq 909 lineage. The four native branches are not identical.

LIGHTS, NOTES AND MENUS

PLAY lights during playback. REC + PLAY means recording. STOP means stopped. PLAY briefly goes dark at the loop boundary, so you can see it come around. The Setup landing page reads "4.5 Loop Bar Seq" above "[1-9] / Slider". The readable 4.2.1 graphics are restored for Setup 7/8/9 and Manage 7.

The accepted fixes for first-note capture, empty-track erase, track handoffs, loop-boundary voice resets and notes crossing the end of the loop remain.

REALITY CHECK

Still an Emax. Dense drum parts and heavy MIDI traffic can make timing wobble. No promise of perfect sync, more voices or modern drum-machine timing.

SE and Standard are the exact owner-approved binaries. HD and Plus are software-verified ports, awaiting compatible hardware testing. The checks execute native/emitted NS32008 instructions with modeled hardware boundaries; they do not measure real audio, MIDI jitter or physical SCSI/floppy behavior.

source/ has rebuild tools and handoff notes. verification/ has the results. release_manifest.json identifies the exact images; SHA256SUMS covers files.

FREE, UNOFFICIAL, AT YOUR OWN RISK

An independent experiment shared free for education, study and tinkering. Not for sale. Please don't sell it or bundle it into a paid firmware pack. No E-mu endorsement, affiliation or official support.

Supplied AS IS, without warranty of reliability, compatibility or data preservation. Back up your samples, presets, sequences and disks. You choose whether to use it and accept the risks. No promise of fixes or support.

To the fullest extent permitted by law, the author, contributors and people sharing this build accept no liability for lost data, malfunctioning or damaged equipment, interrupted work, lost income or other losses from use. This does not exclude rights or liability that cannot legally be excluded.

E-mu, Emax and the original firmware belong to their respective rights holders. An educational purpose is not a grant of redistribution rights.

Now make some music :)

Have fun and pass it around
This is what the internet used to be about.

I make house music as Deep88. The '88' is a tribute to the Second Summer of Love. Go dig into the 1988 revolution and you'll see why.

If you'd like to say thanks, you can send a donation via PayPal to info@deep88.com. Even better, buy some of my music at https://deep88.bandcamp.com. I'd really appreciate it.