Wombat ADB-USB Input Converter

Bridge keyboards and mice with classic hardware!

The Wombat is a bidirectional ADB-to-USB and USB-to-ADB converter for keyboards and mice.

Connect modern USB keyboards and mice to a classic ADB-based Macintosh, Apple IIgs, or NeXT
Connect legacy ADB input hardware to a USB-based computer running Windows, OSX, or Linux

No special software or drivers are needed – just plug it in and go.

Now you can finally use a modern optical mouse with your vintage Macintosh, or amuse your coworkers with a retro ADB keyboard on your work machine. ADB-USB Wombat is an indispensable tool for Apple collectors and enthusiasts.

Optional accessories for your Wombat:

ADB-USB Wombat is great for breathing new life into your vintage Apple hardware collection. If you love old Macs, you know ADB keyboards are expensive and hard to find, and ADB mice are sticky and trouble-prone. With the Wombat, you can substitute modern USB input peripherals instead. Or if you swear by your old Apple Extended Keyboard, you can use it with your modern computer. Visitors are sure to smile when they see you running 1980s Apple input peripherals on your current-year machine.

No external power source needed
On-board power key for remote turn-on
Upgradable firmware
Works with your favorite mice and keyboards

The Wombat was developed by Steve Chamberlin, here at Big Mess o’ Wires. See the blog archive for technical details on its software and hardware.

Compatibility

The Wombat hardware is compatible with all Apple computers, keyboards, and mice with an ADB connector (a 4-pin mini DIN), including most early Macintosh computers and the Apple IIgs, as well as some NeXT computer models. It is also compatible with standard USB keyboards and mice with a USB-A connector. When in ADB-to-USB conversion mode, it works under Windows, OSX, Linux, Chrome OS, or any other operating system that supports USB HID input peripherals.

Security dongles, joysticks, and other less common devices are not supported. The Macintosh Plus, Mac 512K, and Mac 128K computers use an older non-ADB connector for keyboards and mice, and are not supported.

USB to ADB

Connect USB keyboards and mice to a classic ADB-based Macintosh, Apple IIgs, or NeXT computer. Requires an ADB cable (not included). Set the Wombat board’s jumper to USB input mode, as shown on the diagram. Power will be supplied from the computer. Use an ADB cable to connect the board’s ADB port to the computer’s ADB port.

A single USB peripheral can be connected directly to the Wombat board’s USB-A port at CON1, or a standard USB hub can be used to connect multiple peripherals at once. When in this mode, the Wombat supports one USB keyboard and one USB mouse, as well as any number of ADB keyboards and mice, all used simultaneously.

Standard bus-powered USB hubs are recommended. Some externally powered USB hubs (with their own independent power supply) can backfeed power into the Wombat even when it’s off, causing problems.

Right Click Behavior – Most ADB mice had only one button, so the USB mouse’s right button is handled one of two ways. Macintosh mode sends a control + click event to the host, which opens context menus in Mac OS 8 and later. NeXT mode sends a true right click event to the host. The default is Macintosh control + click mode. Toggle between the two modes by clicking the USB mouse wheel button (button 3).

Mouse Wheel Behavior – ADB mice did not have a mouse wheel. USB mouse wheel movements will send up/down arrow key events to the host. This works well for document scrolling and file dialogs. If necessary, this “mouse wheel arrow keys” behavior can be disabled using the custom key mapping tool, described below.

Beginning in firmware 0.3.9, a long press of the mouse wheel button (more than half a second) will change the Wombat’s built-in mouse movement hardware scaling. Each long press increases the scaling by a factor of 2. This is helpful when using certain USB mice whose tracking speed is too slow or too fast even after making adjustments in the host OS’s mouse control panel.

ADB Power Key

Power Key – Original ADB keyboards had a power key – a square or rectangular key with a triangle logo that could be used to turn on some later models of ADB Macintosh computers. There’s an equivalent button on the Wombat board that will function as a substitute power key, even when the computer is off.

Connections for Standby Power

Standby Power – If the Wombat is powered from an auxiliary source (optional), it can continue working even when the computer is off. In this case, the PRINT SCREEN key or F13 key on a USB keyboard will also function as the power key to turn on the computer. To use this configuration, set the board’s jumper to USB+PWR mode, as shown on the diagram (board version 1.1 or later only), and connect a standard USB charger to the board’s USB-B port at CON2. For correct operation, an auxiliary power source must always be present when the jumper is set to USB+PWR mode.

ADB to USB

Connect ADB keyboards and mice to a modern USB-based computer. Requires a USB-Mini-B cable (not included). Set the Wombat board’s jumper to ADB input mode, as shown on the diagram. Power will be supplied from the computer. Use a USB-A to USB-Mini-B cable to connect the board’s USB-B port at CON2 to the computer’s USB port. This is the same cable commonly used to connect mobile phones and other devices to a computer. In this mode, nothing should be connected to the Wombat board’s USB-A port at CON1.

A single ADB peripheral can be connected directly to the Wombat board’s ADB port, or multiple peripherals can be daisy-chained, using the ADB pass-through connector found on all Apple ADB keyboards. When in this mode, the Wombat supports one ADB keyboard and one ADB mouse, as well as any number of USB keyboards and mice, all used simultaneously.

The ADB peripherals will appear as standard HID input devices to modern Windows, OSX, and Linux computers. No special drivers or other software are needed.

Firmware Updates

The Wombat firmware can be updated to fix bugs and add new features. Download the firmware.hex file from the downloads section below, and copy the file to the top-level directory a USB flash drive. The USB drive should be formatted with the FAT32 filesystem. Most USB drives already come preformatted this way.

During the firmware update process, the Wombat board can be powered from an ADB-based computer and ADB cable attached at CON3, or from a standard USB charger and USB-B cable attached at CON2. If powering from an ADB cable, set the board’s jumper to select USB input mode. If powering from a USB-B cable, set the board’s jumper to Standby Power mode (USB+PWR).

Disconnect all power from the Wombat board. Plug the flash drive directly into the board’s USB-A port CON1 – do not use a hub. Hold the board’s power key button while you connect the power source to turn on the board. Continue to hold the button for a few seconds, until the A and B status LEDs begin blinking rapidly. The update process takes about 10 seconds. When finished, the LEDs will blink slowly together, once per second.

During a firmware update, both LEDs are used to indicate update status:

slow alternating blinks of A, then B (1 blink/sec) – bootloader is searching for a firmware file
fast alternating blinks of A, then B (8 blinks/sec) – bootloader is updating the firmware
slow synchronized blinks of A and B together (1 blink/sec) – bootloader finished successfully

If B blinks several times while A remains off, it indicates a bootloader error:

2 blinks – no valid firmware exists on chip, can’t start main Wombat program
3 blinks – no firmware files found on USB drive
4 blinks – error in firmware file (checksum mismatch or illegal data)
5 blinks – error while updating firmware in chip memory

LED Status Codes

The A and B LEDs on the Wombat board display status and error information. (The A LED is labeled RUN on some boards). During normal use, the A LED will turn on when the Wombat has a working data connection (ADB or USB) to the host computer. The B LED will blink whenever there’s keyboard or mouse activity.

Help Commands

You can interact directly with the Wombat by typing help commands on an attached ADB or USB keyboard. Open an empty text document or command prompt on your computer. The Wombat will “type” its responses to your commands, so they appear on the screen.

Control-Shift-Capslock-T – Cycles between key mapping types US-GENERIC (ANSI QWERTY), ISO-GENERIC (UK and other non-US QWERTY), ISO-FR (AZERTY), and ISO-DE (QWERTZ)

Control-Shift-Capslock-G – Shows the currently active key mapping type

Control-Shift-Capslock-V – Displays the firmware version number

Control-Shift-Capslock-I – Displays the USB vendor and product ID or ADB handler ID of the keyboard and mouse

Control-Shift-Capslock-C – Enters keydump mode. While in this mode, the USB key code is displayed for each key that you press, along with the corresponding ADB key code it’s mapped to (or vice-versa). This can be helpful for troubleshooting key mapping problems.

Control-D – Exits keydump mode.

International Keyboards

Non-US international keyboards are supported by the Wombat. These include country-specific keyboard layouts like British, Canadian French, Danish, Greek, AZERTY variants, QWERTZ, and others. You’ll need to select the appropriate keyboard type in your operating system’s keyboard control panel, in order for the key mappings to work correctly.

System 7 Keyboard Control Panel

Two specific keys on ISO keyboards may require extra attention. If the key above TAB incorrectly behaves like the key to the right of LEFT SHIFT, you can switch ISO mode on/off to correct it. See details in the Help Commands section.

ISO Keyboard Key Swap

USB-to-ADB – Best results are obtained with Apple-brand country-specific USB keyboards, or any brand US-layout USB keyboards. In many countries, the country-specific PC-type USB keyboards have a different symbol layout than Apple ADB keyboards. These PC-type USB keyboards may be used, but key mappings for some symbols will be incorrect where differences exist between the Apple and PC-type layouts.

ADB-to-USB with Mac OSX – The first time you connect the Wombat to a modern Mac, a wizard will appear and attempt to detect the keyboard type. For non-US keyboards, you should select an ISO keyboard type from the wizard. If the key above TAB incorrectly behaves like the key to the right of LEFT SHIFT, even when the Wombat is in ISO mode, you may need to delete the OSX keyboard preferences to force the wizard to run again. Set the Wombat to ISO mode, delete the file /Library/Preferences/com.apple.keyboardtype.plist, restart the computer, and follow the wizard steps when it reappears.

Windows 7 Text Services and Input Languages Control Panel

ADB-to-USB with Microsoft Windows – Under Windows, when using country-specific ADB keyboards, you’ll need to select an Apple keyboard sub-type when choosing the keyboard type in the Windows preferences. The keyboard type is selected in the Text Services and Input Languages control panel. E.g. select a keyboard type of United Kingdom (Apple), French (Apple), or German (Apple) rather than the default United Kingdom, French, or German. If you don’t see the Apple sub-types listed, you’ll need to install the Apple keyboard driver applekeyboardinstaller64.exe.

Custom Key Mappings

With firmware version 0.3.0 or later, you can create your own customized key mapping tables. Change which keys behave as Command and Option, reassign the function keys to new purposes, or design other custom mappings. See the Wombat Keymap Tool for details.

What are ADB and USB?

ADB connector

From 1986 through 1998, ADB (Apple Desktop Bus) was the standard system for connecting peripherals like keyboards and mice to Apple computers. It was used by the Apple IIgs, as well as all early Macintosh models except the Mac Plus, 512K, and 128K. The ADB connector is a round mini DIN 4-pin, and is physically identical to the S-Video connector.

USB-A connector

USB (Universal Serial Bus) is the dominant standard today for connecting keyboards, mice, and other peripherals to a computer. Nearly everyone will recognize the familiar rectangular USB-A connector that’s used to plug a device into a host machine. USB replaced a variety of earlier standards like Firewire, ADB, and PS/2. Every Apple computer since 1998 has used USB for its input peripherals.

Converting between the two systems involves more than just a physical plug adapter. ADB and USB high-level protocols are fundamentally very different, and also have different signal speeds, signal formats, and voltages. ADB and USB input peripherals have different communication behaviors too. ADB keyboards and mice use event-based reporting, and only communicate when something has changed, whereas USB keyboards and mice communicate their full current state whenever asked.

Documentation

Instruction manual: Wombat instruction manual

Downloads

ADB-USB Wombat latest firmware version: adb-usb-wombat-0.3.11 (September 28 2026)

Older firmware versions: (try these if the latest version gives you problems)
adb-usb-wombat-0.3.9 (August 9 2023)
adb-usb-wombat-0.3.8 (October 21 2022)
adb-usb-wombat-0.3.7 (September 11 2021)
adb-usb-wombat-0.3.6 (June 25 2021)
adb-usb-wombat-0.3.5 (April 8 2021)
adb-usb-wombat-0.3.4 (April 8 2020)
adb-usb-wombat-0.3.3 (September 19 2019)
adb-usb-wombat-0.3.2 (September 9 2019)

3D-printable enclosure (contributed by James Kelly, Creative Commons license with attribution)

Get One Now

Check out ADB-USB Wombat at the BMOW Store.

301 comments

301 Comments so far

Steve - May 18th, 2021 3:54 pm

The ADB-USB Wombat is now back in stock at the BMOW Store.
Dana Fehr - May 21st, 2021 3:55 pm

I got mine a couple of months ago, and its such a great product. Being able to use an optical mouse on my old mac is great! The funny issue I am having with a Mac LCII is when I power on the machine the A and B lights will flash alternately at about 1second interval. It doesn’t matter rather my usb devices are plugged in or not. Unplugging the ADB and replugging it after the OS starts to boot fixes it until the computer is next powered off.

Any thoughts?
Steve - May 22nd, 2021 4:52 pm

It sounds like something may be holding the power button during power-up, which triggers the bootloader described above. Please use the Customer Support link at top-right if you need help with individual issues.
Jake - June 22nd, 2021 1:33 am

Hi Steve, would it be possible for you to add the date last updated on this page next to the latest firmware version? I check back infrequently as I’m hoping one day a new version comes out that improves the power button behaviour on an AEKII (I e-mailed about inability to map it as an Fn key a while ago) but I can never remember what the last version number that came out was!

Cheers, Jake
Steve - June 22nd, 2021 7:20 am

Done! I’m currently focused on other projects. Rest assured there will be an announcement about any future firmware updates.
Steve - June 25th, 2021 1:31 pm

Jake, Wombat firmware 0.3.6 resolves the power key issue that you encountered. https://www.bigmessowires.com/2021/06/25/adb-usb-wombat-update-power-key-fix/
Jake - June 25th, 2021 9:15 pm

Steve, thank you, that’s awesome. I’ve tested it, and it works great of course. I’ve commented on the blog post my thanks to Alice as well. Outstanding after sales support from your team. 🙂
Kristian - June 30th, 2021 3:00 am

Hello Steve,

I have been using the Wombat for almost two years now (I think), and it is making my typing experience much better since I can use my favourite keyboard, the Apple M0118 with the orange Alps. However, recently I have been trying to find a way to keep dust from settling inside. Have you considered making a more permanent case solution? I started making this enclosure for myself to print, and then I thought maybe this could become a joint venture?
Please, let me know what you think. 🙂

https://imgur.com/a/26wV5Gr

Sincerely,
Kristian Möller (a.k.a. ktkm)
Steve - June 30th, 2021 6:54 am

Looks very nice! The last time I looked, commercial 3D printing and injection molding are both still too expensive for making retail products at this sales volume, compared to laser-cut 2D acrylic. You might considering sharing the model on Thingiverse so people with a 3D printer could make one themselves. You can contact me directly (Contact link at the page’s top-right) if you want to discuss more.
Jake - June 30th, 2021 7:09 am

Kristian, that looks like a good enclosure, it’s the perfect kind of thing to share with the community on Thingiverse.
Kristian - June 30th, 2021 11:59 pm

Thingiverse sounds like a good idea. I’m definitely considering it. Thank you.
Steve, I’ll get back to you when I have a more noticeable product, and perhaps with some questions regarding external LED connections.
BetaC - July 17th, 2021 3:41 pm

Hey, I\’ve managed to get everything set up and working with both a computer and an iPad Pro for the most part, with the only real exception being very specifically my ADB Mouse II not wanting to work with anything but actual ADB computers. I have an original edge-and-rectangle ADB Mouse that works fine, so I think it\’s just the ADB Mouse II. Has this ever been an issue before?
Steve - July 18th, 2021 12:53 pm

There shouldn’t be any issues with the Mouse II. I think its internal electronics are identical to the original ADB mouse, and the only difference is its shape.
Luis Torres - July 19th, 2021 3:59 pm

Hi. I just received the ADB-USB converter with the ADB cable, and it doesn’t seem to work. I have a Macintosh SE 80mb 800k drive with the original ADB keyboard, which works fine with the ADB mouse. I tried to connect an old black usb apple pro keyboard M7803, and even a Logitech usb keyboard and I get nothing. The light on the wombat does go on when connected (I tried hitting the side switch also), and still get no keyboard input
Steve - July 19th, 2021 5:12 pm

For 1-on-1 customer support issues, please use the Customer Support link at top-right, and I’ll do my best to help you troubleshoot. You may just need to set the board’s input type jumper to USB, see instructions above.
BetaC - July 19th, 2021 5:59 pm

Hey, responding to the comment you made earlier, it seems that there’s actually a few different versions of the internals for the ADB Mouse II, all with somewhat different hardware. The mouse that seems to have issues is specifically a Logitech model with an M-AL-APL4 logic board. I don’t have any other ADB II mice at the moment, so I can’t tell if it’s just some revisions. I can confirm that my Gravis Mousestick II (sort of) works as a mouse through the Wombat.
Tom - July 30th, 2021 7:53 pm

Can i use it with JP keyboard? (Maybe my keyboard is JP 108key)
Steve - July 31st, 2021 6:37 am

I haven’t tested it with a Japanese keyboard. I think it’s the same QWERTY layout as US keyboards, so it should be OK.
Chris Peak - July 31st, 2021 9:44 am

Just received a unit – great device, thanks.

Worked like a charm on my 68k machines for MacOS, A/UX and Linux, but NetBSD failed to discover my M2980 keyboard. On boot, the kernel reported “mapped device” (3) not “extended keyboard” (2).

Turned out the Wombat was flashed with 0.3.2 .. so I updated to 0.3.6 and all’s well now!
Chris Peak - July 31st, 2021 10:06 am

Correction: my USB keyboard is an A1243; the M2980 is my ADB keyboard I used as reference.
Roland - September 8th, 2021 12:49 am

I tried to get a keyboard running with the QMK firmware. I’ve configured it to the most compatible mode (UEFI compatible) as possible, but I don’t even get a signal on the Wombat. I wonder, if someone else has tried this, yet, and found a solution?!
안승지 - September 28th, 2021 8:13 pm

Hello! Thanks to your product, I’m using aek II(m3501) well in Korea, and I recently got aek I(m0115) and connected it, but it doesn’t work as I thought.
First, I can’t use the right alt key in aek I, it doesn’t recognized.
and If I connect aek II after connecting aek I, the mapping seems to be initialized.
In order to use the Korean/English conversion in Korea, the right alt key must be available, is there any way?
If possible, it would be nice to use both aek II and aek I together.
Thank you.
Jeff - November 1st, 2021 7:35 pm

Hi,
In case it helps anyone else, my observation is that a known good Razer DeathAdder Elite Gaming Mouse doesn’t seem to work from USB->ADB mode. I’ve confirmed the Wombat is working with a USB keyboard, but no luck with the mouse either through a USB hub or plugged directly.

I’ll try out a different mouse when I can get my hands on one.
Jeff - November 13th, 2021 11:33 am

I’ve confirmed that the Razer DeathAdder Elite Gaming Mouse does not work, even when directly connected as the only device. Maybe a power-draw issue because of the gaudy LCD lighting of the mouse?

My working config at the moment is K-CEVE 4 port USB Switch w/ Touch ID Magic Keyboard + Magic Trackpad. It’s a pretty nice setup that toggles a single keyboard+mouse between a modern Mac, modern gaming PC, and vintage PowerMac 6100. Love it! 😀
Waylon - December 27th, 2021 10:34 pm

Hi folks: I’m interested in using the Wombat to connect an Apple Extended Keyboard ii to a M1 Macbook pro. The new laptops only have USB-c inputs. Is there any problem going from your mini-USB to USB-c? And is there anything about the new M1 machines that would cause trouble when using the Wombat? Thank you!
Steve - December 28th, 2021 10:39 am

It works fine on an M1 Macbook Air. You’ll just need a USB-C adapter, same as for any other USB peripheral.
Phil Fuster - January 24th, 2022 2:07 pm

Do you have anything that will allow me to plug in a non-ADB mouse into a NeXT Keyboard. I need to find a mouse for my next workstation and cant find one.
Steve - January 24th, 2022 9:37 pm

Sorry, no. For NeXT-specific hardware needs I suggest you try here: https://www.blackholeinc.com/specials/blackhardware.shtml
Chris Peak - January 31st, 2022 8:34 am

Steve,
Is there a way to configure things for option-booting a Mac? I have a USB keyboard connected through a Wombat running 0.3.6 firmware into a Beige G3 which I need to option-boot, or to Opt-Cmd-O-F boot into OFW. The option and command key combos don’t seem to be seen at boot-time.
Steve - February 1st, 2022 8:38 am

Hmm that’s strange. The Wombat is doing low-level ADB/USB conversion and doesn’t know or care about what operating system or bootloader is running. You could try it after rebooting the computer instead of from a cold start with the power switch. Or you could fall back to a different keyboard for times when you need to access the firmware menu.
Chris Peak - February 1st, 2022 12:08 pm

I’ve tried assorted unpowered and powered USB arrangements without success.

No joy on warm restarts either.

Bootrom keyboard combinations are also ignored with the Wombat connected to my Quadra 650 — so it’s not a peculiarity of the G3.

I updated to firmware version 0.3.7 but no change.

The G3 is awkward in only having a single ADB port so I can’t have a second fall-back keyboard always attached.
Chris - February 1st, 2022 9:44 pm

Option-command-whatever doesn’t work with any of my Wombats with any of my m68k Macintoshes, either, so I use the PRAM-zapping feature in Tech Tool Pro when necessary.

It seems like the Wombat is waiting for some sort of a handshake from the Mac before it starts to send ABD data.

I solved the single-ADB port problem by soldering a S-video jack onto the unpopulated footprint on the Wombat. ADB devices can be daisy-chained through the Wombat just fine.
Chris Peak - February 2nd, 2022 11:23 am

Thanks for confirming this behavior.

The daisy-chaining suggestion with an extra jack sounds most useful. And presumably a standard S-video splitter cable would work too.
Dan Draper - February 4th, 2022 1:11 am

Hi Steve! I have a question about hot-swapping input devices when using the Wombat to connect a USB mouse and keyboard to a classic Mac’s ADB port. Obviously ADB is not hot-swappable, but I’m wondering if the Wombat allows for hot-swapping USB devices while plugged into a running classic Mac. Specifically, I want to set up my SE/30 next to my MacBook Pro on my desk and have them both running throughout the day, swapping the keyboard’s USB port back and forth to the one I want to use. Is this possible? Would it create any issues on the ADB machine or does the Wombat account for the plug-and-play change of input? Thanks!
Steve - February 5th, 2022 12:01 pm

A KVM switch may be a cleaner solution for that situation, rather than repeatedly plugging and unplugging the keyboard. The Wombat firmware wasn’t designed for the idea of dynamically adding and removing USB devices after power-up, but I think it should still work for this example.
Adam - March 8th, 2022 4:47 pm

I have a bunch of old ADB based Macs and an IIgs. Would it be possible for me to connect my Wombat to an S-Video switch in order to have a single keyboard and mouse connected to all four machines?

I remember being told back in the day never to connect a ADB keyboard after the machine was turned on, so I assume the process to go from Mac #1 to Mac #2 might be something like:

1. Turn off Mac #1
2. Press button #2 on S-vide switch
3. Turn on Mac #2

Do you think that would work?
Steve - March 8th, 2022 5:11 pm

Although ADB cables have the same physical connector as S-Video, I don’t think an S-Video switch could be used as an ADB KVM. A proper ADB KVM would need to have an internal processor capable of handling the ADB protocol.
Adam - March 16th, 2022 8:34 pm

Steve,

Thanks for the quick feedback. I was at Walmart and saw a GE branded S-Video switch for $15 so I decided to buy one to see how if it would work. For testing, I used two V1 B&Ws as I figured I could fall back to USB if I blew out the ADB port. My configuration was as follows: Port 1: B&W, Port 2: B&W, Output: Apple Design Keyboard & Mouse. Based on limited testing, it does appear that an S-Video switch can be used to toggle between machines. However, detection is a bit spotty — sometimes the machine boots with a working keyboard and mouse and other times it doesn’t. Also, I found it a bit troubling that each B&W would turn on immediately after plugging in the S-Video cable into the machine — it makes me feel as though something isn’t 100% correct with the electrical signal.

Having established partial compatibility, I turned to the Wombat, subbing in the Apple Keyboard for a USB keyboard & mouse. This configuration always resulted in no detection. I thought perhaps the Wombat wasn’t getting sufficient power so I switched it to USB Power mode but it didn’t make any difference.

Anyway, I hope this might help someone else. Also, I read you blog about coming up with new products. Perhaps a reliable ADB switch might be worth looking into? 🙂

Best of luck,
Adam
Aaron Newman - March 30th, 2022 9:57 am

How would one go about updating the firmware on a version 1.0 RetroUSB board? I have an early one and it seems to not work with my powermacs for USB to ADB.I see this issue is resolved in firmware 3.1. I created a FAT32 thumbdrive and copied the firmware.hex file to the USB and loaded it but nothing appears to happen when powered up. Going to buy a newer one in the meantime. Thanks
Steve - March 30th, 2022 12:53 pm

All versions of the Wombat use the same firmware update method, including the original Retro USB before it was rebranded. Make sure the firmware.hex file is in the root (top-level) directory of the USB drive, and follow the instructions in the Firmware Updates section above, making sure to hold the button for several seconds until the LEDs begin blinking rapidly.
Aaron Newman - March 30th, 2022 4:11 pm

Thanks for the reply! I figured it out. On the Retro USB you need to put it in “USB” mode to update. I had it in ADB mode. The instructions didn’t match my jumpers so I wasn’t sure. So update worked and its working with my other mac now.
Second question if you know. Is there a way to use this with a USB KVM. I found the KVM wont see and connect to the retro USB even when powered via CON2. Seems like its providing the USB connection later than the RetroUSB likes possibly. The KVM doesn’t seem to provide the KB and Mouse until it sees the USB connection. Or maybe its the way the USB devices are presented? Works great ADBtoUSB and USBtoADB directly connected. And the KVM works fine on the macs that have a USB port (sonnet tempo PCI).
Steve - March 31st, 2022 7:10 am

If you’re using a USB KVM, then the Wombat is a USB device and ADB host, so you should set the jumpers for ADB input. There are several people using the hardware successfully with a KVM – check out some of the older comments here.
Matt - April 5th, 2022 8:55 am

Very happy to be able to drag my Apple Extended II out of the closet and use it with my macbook. The only problem I’ve had is trying to remap the caps lock key to control. I’ve already modified the switch in the keyboard so it doesn’t lock.

First I tried remapping it in in the Keyboard preferences pane. It seemed like whenever you pressed the caps lock key, you would get a key down event, followed by a key up event. Then when you release the key you get another key down followed by key up. I also tried remapping it using the keymap on the wombat itself. However it seemed that if I map caps lock to anything other than caps lock, it doesn’t register any keypress events at all.

I’m not sure what the events actually look like at an ADB level. I suspect that the keyup + keydown behavior is being synthesized by the wombat to emulate the behavior of a non-locking caps lock key. If so is there some way to turn this behavior off?
Steve - April 6th, 2022 12:06 pm

Attempting to remap Caps Lock will lead to problems, as you’ve discovered. The Wombat uses Caps Lock internally for all of its help commands, and also synthesizes needed keyUp/keyDown events to provide expected Caps Lock behavior for USB computers. This is a baked-in firmware behavior and can’t be modified.
adam - May 12th, 2022 8:22 pm

i need my G4 QS to turn on Via a Performa ADB keyboard. has anyone made a firmware mod to translate the power button into a discrete trigger output that i could use via a relay to close the front panel power button?
thinking i could use an arduino to sniff the usb packets and watch for the power button scan code but i figure the wombat is already configured to do just this so if it could just give me any kind of output from the board itself – i could make this work pretty easily.

thoughts?
Götz - May 12th, 2022 11:42 pm

Re: turning on a G4 remotely. I’d opt for a simpler solution. Choose “start after power delivery” (or how it’s called) in the OS X energy control panel. Then plug your G4 into a RC enabled power distribution socket for ~15€, and as soon as the G4 gets power, will switch on. Worked for me. Don’t know if it would work with Mac OS 9, too, though.
Daniel - June 15th, 2022 12:09 pm

Hi Steve, thanks so much for The Wombat
It works fine with ADB Swiss French keyboards on macOS. I’ve just notice a minor issue when using commands, on the Swiss keyboards the Z and Y keys are inverted, therefore the command Control-Shift-Capslock-I returns

Mouse id FF, kezboard 04

other useful info if needed:

Console input is ISO GENERIC
ADBÙSB Wombat firmware 0.3.7

USB Wombat:
Product ID: 0x01a9
Vendor ID: 0x04d8 (Microchip Technology Inc.)
Version: 0.03
Speed: Up to 12 Mb/s
Manufacturer: Big Mess o’ Wires
Location ID: 0x02100000 / 7
Current Available (mA): 500
Current Required (mA): 100
Extra Operating Current (mA): 0
Christophe from France - July 13th, 2022 1:26 pm

Hello Steve ! and thanks for the Wombat ! I love it ! I’m doing few video about the use of the Wombat ! The first one it is about connecting an ADB keyboard to a modern Mac and upgrade the wombat. I’ll then do another for USB keyboard on a IIGS 🙂
Hope you’ll like them !
The first one : https://youtu.be/AjTytP28qvw
And thanks again for this very VERY useful tool !

Best regards from France !
tim1724 - October 14th, 2022 5:38 pm

I just noticed that with an Apple A1243 keyboard the command/option modifiers are ignored when I press control-F13. (e.g., to reboot my Apple IIGS with control-command-reset). It acts just like I’d pressed only control-reset. The command/option keys work any other time (e.g., for menubar keyboard equivalents), just not while I’m pressing control-reset. Also, occasionally when I try to use control-command-reset with this keyboard the computer hangs for a second or two, as if I were continuing to hold down the reset key. So it seems like there’s some weirdness with sending the key-up event for the reset key in this situation.

But with a generic (e.g., Dell) USB keyboard I can press control-windows-PRtScn and it works fine to reboot. Or control-alt-windows-PrtScn to start the IIGS self test, etc. Wacky.

It was doing this on firmware 3.3.3. I upgraded to 3.3.7 (confirmed with control-shift-caps-V) and it still does it. 🤷🏻‍♂️
It’s not a big deal. I prefer to use the Apple keyboard (due to the built-in hub, so I can plug in the mouse) but I can just use my joystick buttons instead of the command/option keys in this situation if necessary.

I do have a very early “retroUSB 1.0” board, but I added the extra 1000µF cap to make it work with the Apple keyboard.
Steve - October 17th, 2022 9:04 am

Hi Tim, the A1243 keyboard works fine with the IIgs in our testing. With all Apple II keyboards, you need to continue holding Control and Command (or Open Apple) for a moment after you release the Reset / Power key, or else the computer may misinterpret the key combination. If you need further help, you can contact BMOW directly using the Customer Support or Tech Support links.
teaeles - December 19th, 2022 10:13 pm

Hello.
I’m using the adb-usb wombat with apple adjustable keyboard.
I updated the wombat to the latest firmware.

I’m trying to swap “Caps Lock” with “Left Control” using either the keymap tool (on your website) or apple’s system settings app, but no avail.

To be more specific, here is what happed.
System Settings: no change (default setting restored)
Keymap tool:
– caps lock -> left control
– left control -> caps lock
Then the caps lock key lost its modifier functionality and does not affect what I type, i.e., when I type “caps lock” and “a” at the same time, simply “a” is typed.
The left control key behaves as if it were “caps lock”.

How can I solve this problem?

System: Mac Studio running macOS 13.1
Wombat: Firmware 0.3.8
Keyboard: Apple Adjustable Keyboard

Thank you.
Mike - December 19th, 2022 10:24 pm

What’s the size limit for a thumb drive that can be used to upgrade the firmware / re-map keys? The smallest thumb drive I have is 16GB, and it wouldn’t work. I made sure it was formatted FAT32– I even formatted it and loaded the files on a PC to make sure MacOS wasn’t doing something wonky.

I managed to find an old 2GB SD card, plug it into a SD-to-USB reader, and that worked perfectly. I would have hated to buy a smaller thumb drive on Amazon just to do that.
Steve - December 20th, 2022 8:04 am

Caps lock is a special case and can’t be reliably remapped, sorry. A few limitations are mentioned at the top of the Keymap Tool page. There’s no size limit for the USB drive, so probably something else was happening there. I’ve personally used 16GB and 32GB.
Derek - December 28th, 2022 8:36 pm

Hey, my wombat works fine with my Mac but even when I plug the wombat into a windows machine without the keyboard connected it goes crazy and just keeps typing out a string of characters anyone else having this issue? I updated to 3.8 as well.

THanks
DG 410 - January 16th, 2023 9:11 am

Having issues with one of my Wombats.

So, I have two Wombats, one for my Mac II and the other for my Performa 636 CD. Both are connected to a Belkin SOHO KVM via USB and are currently controlled by PS/2 keyboard and mouse since it’s the only console input I can utilize.

The Mac II Wombat has firmware 0.3.2 and that works fine. Can control with PS/2 inputs flawlessly.

But, the Performa 636 CD Wombat with firmware 0.3.8, I could not get a response from it via PS/2. I tried all firmware updates on this page. None of them worked for me in this case. I did try connecting USB keyboard and mouse directly into the Wombat itself, which does work that way as intended. So, I’m pretty sure it’s not the unit itself.

So, any chance I can get firmware 0.3.2 since I believe that’s the version that works best for this case? Or any chance for a firmware update to address this? I could try another KVM, but the Belkin SOHO that I’m using is the only one that I have that works best for what I’m currently setting up.
Steve - January 16th, 2023 10:49 am

I’ve added some older firmware versions to the download area. Please use the Customer Support link if you need additional troubleshooting help with your specific setup.
ThatKomputerKat - January 19th, 2023 10:55 pm

Two separate things:
The Wombat kept telling me no firmware file was found. After failing by formatting it FAT32 with MacOS disk utility, I found a freeware program at https://www.sdcard.org/downloads/formatter/ and that the stupid thing to show up.

Anyway: Currently when using it in ADB input mode on the Apple Adjustable Keyboard the Wombat doesn’t pickup the volume keys. Like nothing happens in keydump mode. Is there anything in particular that prevents it from picking those up and mapping them to Fkeys?
Steve - January 20th, 2023 8:12 am

There’s a list of Wombat-mappable keys in the Keymap tool here: https://www.bigmessowires.com/wombat-keymap.html The Wombat isn’t designed for USB consumer media controls like volume, eject, screen brightness, or other similar inputs, sorry. Key translation is provided for USB HID group 7 (standard keyboard) as shown at http://www.freebsddiary.org/APC/usb_hid_usages.php and ADB keys as shown at https://i.stack.imgur.com/LD8pT.png
ThatKomputerKat - January 20th, 2023 2:31 pm

I wasn’t talking about USB media keys but OK. I’m talking about ADB media keys on an ADB keyboard. They don’t register as anything. I just though it’d be neat if they could be mapped to Fkeys when connected to a modern computer.
stynx - February 4th, 2023 5:05 am

I am using an original “Apple Extended Keyboard II” with an uKey ADB2USB converter. This setup is connected to a KVM switch. One of the connections of the switch is then routed to the Wombat wich is connected to a Mac ADB port. Sadly the original power key (key code 0x66) is not mapped as standard and sometimes the Wombat stops working when the mac is doing stuff and i switch the input of the KVM (The wombat has USB+power jumper set). Other than that, everything works. I am happy to be able to connect the Mac to my normal setup and don’t have to use a separate monitor and keyboard.
Dave Vondle - February 21st, 2023 9:44 pm

I have a DIY USB HID keyboard that I can’t get to work. The keyboard is this one: https://www.aliexpress.us/item/3256804352610546.html The firmware on the keyboard uses “VIA” (https://www.caniusevia.com/) as a configurator.

The keyboard works fine on a current mac and windows, but it does nothing when connected to the wombat. Is there any way I might get it to work?

Thanks, Dave
Dave Vondle - February 22nd, 2023 8:43 am

I ran the USB HID report through https://eleccelerator.com/usbdescreqparser/ and got this, if this is of any help:

0x05, 0x01, // Usage Page (Generic Desktop Ctrls)
0x09, 0x06, // Usage (Keyboard)
0xA1, 0x01, // Collection (Application)
0x05, 0x07, // Usage Page (Kbrd/Keypad)
0x19, 0xE0, // Usage Minimum (0xE0)
0x29, 0xE7, // Usage Maximum (0xE7)
0x15, 0x00, // Logical Minimum (0)
0x25, 0x01, // Logical Maximum (1)
0x95, 0x08, // Report Count (8)
0x75, 0x01, // Report Size (1)
0x81, 0x02, // Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
0x95, 0x01, // Report Count (1)
0x75, 0x08, // Report Size (8)
0x81, 0x01, // Input (Const,Array,Abs,No Wrap,Linear,Preferred State,No Null Position)
0x05, 0x07, // Usage Page (Kbrd/Keypad)
0x19, 0x00, // Usage Minimum (0x00)
0x29, 0xFF, // Usage Maximum (0xFF)
0x15, 0x00, // Logical Minimum (0)
0x26, 0xFF, 0x00, // Logical Maximum (255)
0x95, 0x06, // Report Count (6)
0x75, 0x08, // Report Size (8)
0x81, 0x00, // Input (Data,Array,Abs,No Wrap,Linear,Preferred State,No Null Position)
0x05, 0x08, // Usage Page (LEDs)
0x19, 0x01, // Usage Minimum (Num Lock)
0x29, 0x05, // Usage Maximum (Kana)
0x95, 0x05, // Report Count (5)
0x75, 0x01, // Report Size (1)
0x91, 0x02, // Output (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position,Non-volatile)
0x95, 0x01, // Report Count (1)
0x75, 0x03, // Report Size (3)
0x91, 0x01, // Output (Const,Array,Abs,No Wrap,Linear,Preferred State,No Null Position,Non-volatile)
0xC0, // End Collection

// 64 bytes
Eric - February 22nd, 2023 9:13 am

Just received my Wombat yesterday, and it’s working perfectly aside from a few things I’m trying to program (2 questions). (Q1) I’d like to get my function keys mapped to the same shortcuts my MBP’s built in keyboard uses. I’ve had success with mapping F10-12 (volume) with the custom keymap tool, and success with F1-4 using my Mac’s System Settings. I’d like to get F5-9 working if possible without purchasing any premium software: F5=Siri, F6=Focus, F7=Media previous track, F8=Media play/pause, F9=Media next track. Additionally, I use YouTube Music as my music player through Chrome. (Q2) Any idea if it’s possible to execute this without having to change to the music tab each time? I’ve tried a few tactics that I came across in these comments, but no dice so far.
Steve - February 22nd, 2023 10:35 am

@Dave the Wombat’s HID parser is part of the Microchip microcontroller USB library, it’s not as complex as what you’d find in a full OS like Windows, so you may need to modify your programmable keyboard to present an HID descriptor that’s more like what a standard keyboard uses. If you have another keyboard that’s working, I’d suggesting cloning its HID descriptor as a starting point.

@Eric I don’t have much experience with application-level key macro software for OS features, sorry. Maybe some other readers will have suggestions.
Dave Vondle - February 22nd, 2023 12:03 pm

Thanks @Steve, I don’t have access to the source files of the firmware unfortunately. When looking at the descriptor, it seemed to be in line with what I picked up from you in other comments (namely Usage Page = 0x07) Is there anything that looks non-standard to you?
DBJ314 - March 22nd, 2023 12:05 pm

I got a Wombat a few years ago and enjoy it quite a lot. It lets me use a Kensington Turbo Mouse (really a trackball) with my modern laptop. But one thing I have been missing is an easy way to scroll. It would be really nice if holding down one of the buttons on the Turbo Mouse would make moving its trackball scroll up and down instead of moving the pointer. Is it possible to write a firmware update for the Wombat that adds that feature? The Wombat only generates events for three of the four buttons on the Turbo Mouse, so the last button has no effect right now and can be freely repurposed.

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