Using the mods

Everything you need to build the update, put it on your CDJ-900NXS and use each mod. The player must run the official firmware 1.31; the patcher only accepts that update.

Install

1. Get the official C900NXS.UPD for firmware 1.31 from Pioneer DJ. The patcher checks its SHA-256 and refuses any other file.
2. Run the patcher with Python 3. Tick the mods with the arrow keys and Space, build with Enter.
   $ python cdj900nxs_patcher.py C900NXS.UPD
   Ticking a mod also ticks what it needs (utility needs code, hotcuekeys needs cuecolours); unticking one unticks what depends on it (beatjump needs hotcuekeys). credit (ticked at the start) makes the boot screen say Pionope Mods by Givou where it said Ver 1.31; untick it to keep the stock text.
3. Read the disclaimer and type yes to accept it. Nothing is built without it.
4. The new file is written to out/<date>-<mods>/C900NXS.UPD, with a report.txt listing every check.
5. Copy C900NXS.UPD to the root of a FAT32 USB stick and run the update from the player as you would for an official update.

Without a terminal that can read single keys, name the mods instead and accept the disclaimer with --accept:

Back to stock

Build the original application, relabelled so the player accepts it, and update as above:

Keep this file on a stick before you try any mod.

code arnoldasr

Three display changes tested together as one build: the detail waveform in RGB colours, the BPM shown with two decimals (stacked beside the tempo) and a two-line phase meter.

utility arnoldasr

UTILITY › SLIP FLASHING becomes PHASE METER; its value chooses which phase meter is shown. Needs code.

overview arnoldasr

The overview waveform's colour table becomes a red-to-white gradient. Data only, no code.

cuecolours ours

When a track is loaded the player asks its database for the cues. This mod also asks for the extended cue list (the one newer players read from rekordbox's export), which carries the colours and the hot cues.

• Memory cues are drawn in the colour set in rekordbox, on the overview and on the detail waveform. A memory cue without a colour, or one stored on the player, stays red.
• Hot cues A–H are drawn as small boxes with their letter, in their rekordbox colour (green when none was set).

hotcuekeys ours

The CDJ-900NXS has no hot cue pads. This mod lends it three: the top three BEAT DIVIDE keys left of the jog. It needs cuecolours, which reads the hot cues from your USB.

The hot key mode

1. Open UTILITY (hold MENU) and set HOT CUE KEYS to ON. The player remembers it.
2. Press QUANTIZE briefly: the hot key mode switches on, and a red HOT KEYS box appears beside the QUANTIZE label. Press briefly again to switch it off (the box turns grey).
3. Hold QUANTIZE for about a second to switch quantize as usual.

In the mode the BEAT DIVIDE keys are hot cues, top to bottom:

1/4 and 1/8 do nothing in the mode and stay dark: the player has three hot cue buffers, and A–C keep them, so each of the three starts at once.

With the mode off, or HOT CUE KEYS set to OFF, the keys do what they always did.

Play a hot cue

Press the key briefly. The deck jumps to the hot cue and plays — also when it was paused.

Gate

Press the key and keep holding it. The deck jumps and starts playing at once, exactly as with a short press; nothing waits. When you let go:

• held less than 0.5 s: it simply plays on (a normal hot cue);
• held 0.5 s or longer: it jumps back to the hot cue and stands there, ready to go again.

Set a hot cue

On a key without a hot cue (LED off):

1. Pause the deck at the place you want.
2. Hold the key for 0.8 s. The hot cue is set there in green, its LED blinks twice and then stays dim, and the box appears on the waveforms.

Keys that already have a hot cue are not overwritten — delete the old one first.

Delete a hot cue

1. Hold DELETE (beside MEMORY under the screen).
2. While holding it, press the hot cue key. Its LED blinks twice and goes off, and the box disappears from the waveforms. You can delete several keys while holding DELETE.
3. Let go of DELETE.

The LEDs

In the hot key mode the LEDs of 3/4, 1/3 and 1/2 show hot cues A–C; 1/4 and 1/8 are off (SLIP no longer changes them):

Good to know

• Set and deleted hot cues are saved on the USB stick, in the track's rekordbox analysis files, the same way MEMORY and DELETE keep memory cues. Like MEMORY, this works once the track has settled, a few seconds after loading.
• A–C start at once. After a track is loaded, once the deck stands at its CUE point for a second in the hot key mode, hot cues A, B and C are loaded silently into the player's three hot cue buffers (about three seconds) and the deck goes back to its CUE point. If you press PLAY or CUE meanwhile, it waits for that (PLAY then plays); a hot cue key pressed meanwhile cuts it short and plays.
• A hot cue you set later loads into its own buffer on its first press (about a second) and starts at once after that.
• Hot cues D–H from rekordbox are shown on the waveforms but have no key.
• A hot cue played from a buffer leaves the CUE point where it is. A gate's release stands at the hot cue; PLAY then plays from there.
• A key pressed while a hot cue is still loading waits for it (the last key pressed wins).
• No slip hot cues yet: with SLIP on, a hot cue plays as without SLIP.

beatjump emulator only

With UTILITY › BEAT JUMP set to 1, 2, 4 or 8 (the item replaces SCREEN SAVER; the screen saver stays on), TRACK SEARCH ⏮ ⏭ jumps that many beats back or forward along the beat grid, keeping the position within the beat. OFF restores TRACK SEARCH.

• While playing, the jump target is loaded into a buffer of the player that only beat jumps use, so hot cues A–C stay ready. There is a short silence while it loads, but the deck comes back in phase, as if it had played on through the jump: the load time is measured on every jump and allowed for, at the deck's tempo. The CUE point stays.
• Paused, the jump is a CALL: the deck and its CUE point move by that many beats.
• A press while a jump or a hot cue is still loading is ignored, so loads never overlap.
• A jump while a loop plays ends the loop; LOOP IN / OUT work again right after a jump.
• Needs hotcuekeys (its engine makes the jumps); the HOT CUE KEYS item may stay OFF.

ledsaver emulator only

UTILITY › LED ANIMATION (the last item) is ON from the first start; set it to OFF to switch it off (the player keeps the choice). When the player's own screen saver dims the display (5 minutes without a track loaded, or 100 minutes paused or at the cue), the LEDs play a loop of about three seconds:

• the BEAT DIVIDE keys fade in a wave from top to bottom and back up,
• SYNC and MASTER, MASTER TEMPO and DISC EJECT fade in and out against each other,
• CUE, PLAY, REV, SLIP, the SLIP LOOP bar and RELOOP/EXIT light one after another,
• the jog's three rings light in turn: inner, middle, outer, middle, inner …

Any key ends it, as it ends the screen saver. The keys without levels (CUE, PLAY …) can only switch on and off; the rings too.

Test status

FAQ

Does this touch the boot loader?

No. The patcher copies the boot loader and recovery loader from the official file byte for byte and checks them again before writing. Only the main application changes.

Can I go back?

Yes, build --stock and run the update. Keep that file ready before flashing mods.

Do I need rekordbox?

Cue colours and hot cues come from a USB stick exported with rekordbox. Without them the mods show what the stock player shows.

Why is the version still 1.31?

The update file says 1.32 so the player installs it; the application inside still reports 1.31 (in UTILITY and on the LINK screen). Only the boot screen says Pionope Mods by Givou instead of Ver 1.31.