Programming KBD Keyboards via Bootmapper Client (TMK guide getting added soon here!)


I'm used to paying $350+ for custom aluminum keyboards, but was totally shocked when I received my $160 KDB75. The keyboard was packaged extremely well and arrived from China with no flaws, and weighted far more than I was expecting. It weighs more than my RS96. I never was really into the 75% layout, but I was never into the 96 key layout until I tried it, so I figured I'd give it a try since the price was definitely right.
But enough of the "review" part, lets get on to programming this guy. I always like to do guides because I know that being intimidated by programming a custom can often lead to people skipping buys they would otherwise join. This is a very easy one to program, so nothing to be afraid of here!
The first step is to simply download the Bootmapper client found here:
After downloading it and running the .exe (I'm on Windows, there is an OSX version as well) you should see something like this:
The very next thing you will need to do is press the "Download" buttom:
This essentially grabs the layout that is currently on the keyboard and imports it into the Bootmapper program. You should see something like this now:
This is showing you the current matrix. Don't worry, you don't have to edit the layout by finding the key you want to change directly from here, there is a much more intuitive way. Simply click the "Toggle bootmapper" button:
Now that the bootmapper button is active, you will not be able to type normally. So during this process you can't swap back to browsing the web or typing in Slack, etc.
Once this is active you will press the key you want to remap, and it should get highlighted in red within the matrix. Simply click on the key you want to change it to from the selection of keys at the bottom. It should look like this, using Caps Lock as an example:
Make sure you uncheck "Apply to all layers" if you are doing anything on one of the FN layers! Otherwise this will change the key on every layer!
Now, speaking of FN layers you have up to three available, as you can see in the top left corner. This works just as programming any layer, simply click the layer button first, and then while in bootmapper mode hit the key you want to reprogram. Just be sure toset a FN button on your main layer so that you can access it. Bootmapper gives you easy toggle buttons for layers 2 and 3 (meaning hit it once and it stays on, hit it again to turn it off). This can be very useful for alternate layouts like DVORAK or if you want to set up a full layer of macros for a particular game.
One more very important thing to point out is lighting controls. You will probably want to put these on the normal FN layer. RGB mode controls the SMDs on the PCB for underglow, and LED mode, LED BrUp, LED BrDN only affect in switch LEDs. the LED on/off affects both.
Moving on to lighting!


To access the lighting features (both under PCB SMDs and in-switch LED's) go to Options from the main tab selection. You should see this screen:
At this menu the left side is all for controlling the SMDs for underglow. There are five effects: Fading, Immediately, Sequential, Static, and Flow. In-switch LEDs only have a Fading effect, or on/off at adjustable brightness levels.
Now lets head back to the main tab to flash the new layout to the keyboard. Make sure "ps2avrGB & ps2avrGB_split" is selected as the target:
After you have everything set just as you want, return to the main tab and click the "Upload" button. Make sure to have "Reboot after uploading" checked. This will now flash the new layout to the keyboard, and immediately restart it, leaving no need to unplug and replug the keyboard in.

Hopefully this got you off to a good start programming your keyboard! As always there is more that Bootmapper is capable of and I will document some of the more advanced features soon! Fow now feel free to ask any questions you may have though and I'd be more than happy to lend a helping hand!
thumb_upsteve, WhisperingWindsOfShit, and 47 others

Aug 19, 2020
I know that your post is already a few years old but I have just encountered a big problem. I accidentally hit "Upload" instead of "Download" right after opening Bootmapper Client and now the keys on the keyboard are not registering anymore. Restarting my PC didn't help. Did something similar happen to you? Do you know how to fix it? Thank you
May 30, 2020
Thanks so much for this guide! It really helped me get started with my new keyboard haha. Just wondering, is it possible to have set different underglow lighting schemes so i would be able to identify which layer im in?
Nov 13, 2019
Hey guys I've just got my new Alt yesterday and am already having some teething issues with it. Initially I plugged it in to USB 2.0 standard keyboard port on my work desktop. After using it awhile, the keyboard just goes to sleep and the orange light appears at the bottom. What does that mean? And no keystrokes will work after that unless I unplug and replug my keyboard. So I decided to try using USB 3.0 on my desktop. Incase the reason behind it was that the 2.0 wasn't providing enough power to the kB. I left my desk for a moment to chat to someone for around 5-10 mins. When I came back to my desk my CPU went to sleep which is normal, however the keyboard is now showing the orange light at the bottom and doesn't wake up unless I unplug and replug the cable again. Does anyone have experience with this issue? If so please help. Thanks guys. Happy clacking!
Aug 23, 2019
Im getting the following error :"Error setting action: communication error with device" when i hit the download button
Jan 3, 2018
Hi All, I'm interested in KBD75 keyboards. I'm using MBP with OS and Win10 as well (Boot camp). Could you tell me if there is any option to program this keyboard with two programs - first for Mac OS and second for Win10 and switch them using only two keycaps? Thanks
Nov 21, 2017
I am KBDfans :P
Nov 13, 2017
Thanks for your tutorial! I've never programmed a keyboard befor... sorry if this is a stupid question: Can I use a nordic layout with bootmapper too, let's say to use "Umlaute" like äöü? Is it possible to use one key for different functions without changing the layer? For example: Capslock+i for pageUp, Capslock+k for pageDown?
Oct 28, 2017
Anyone who just got the latest round of KBDFans75 boards - I wrote a half-ass "How To" guide to get the keyboard programmed. Find it here -
Oct 26, 2017
Has anyone who recently bought a KBDFans75 run into trouble with trying to download the initial keymap? Some of us are running into an error of: "Error opening ps2avrGB device: The specified device was not found"
Oct 28, 2017
Rad, thanks again! **scurries off to program a keeb**
same problem mate
Aug 14, 2017
Hi, any chance you can provide me with .hex layout file for the KBD75 for bootmapper? I accidentally deleted my layout pressing upload instead of download. Silly me! Just an brick of aluminium ATM... :(
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Mar 1, 2021