Firmware

M0110 - Vial - to configure keymap you will need to download vial.
M0110A - Vial - FOR PRO MICRO ONLY - to configure keymap you will need to download vial.

Pi Pico MCU firmware coming shortly.

Assembly Instructions

Hi! Sorry for the delay on this, I got no-fault evicted and didn't (and still haven't) have time to build my copies of the production PCBs, which is what I was waiting on to provide detailed instructions. I've still got a lot of unpacking to do so I doubt I'm going to be able to update this with pictures from the final run for a while, but I can at least show you the general gist with the prototypes (not much has changed).

For all PCBs

Cable Making
On a 4p4c connector, the pinout goes something like this. I've labeled the pins on the connector, along with the PCB pins that connect to them:

If you put your 4p4c socket into the PCB, and plug in your cable with one end cut off and the interior wires stripped, and multimeter each pin of the cable to each wire, you can figure out which interior wire colors correspond to which pin. I strongly recommend doing this method rather than trying to fly by eye, because crossover cables are quite annoying. But you can also figure this out by eye, just look at the colors of the cables through the connector and line them up with the pins on the socket. Write down the color to pin matchups.

You MUST use Pin 4 for USB ground (the black wire, goes to USB2 on M0110A and J2 on M0110) but beyond this you can match them up to the other wires in your USB cable however you'd like.

Cut the micro end off a micro USB cable with enough give to get you from the Pro Micro's port to the spots on the PCB. You'll either solder the individual wires into the USBX holes you choose on M0110A, or scroll down to the end for M0110 instructions.

After this, look at the pin numbers to color associations you wrote down before, and add the USB wire colors to each pin (making sure Pin 4 is USB ground). Strip the USB-A end of the microUSB cable, giving yourself enough room to slide the big heatshrink over the whole thing and the little heatshrinks over each individual wire. Now strip all the interior wires on the 4p4c cable you're using. Splice the stranded wires together using your preferred technique (I do the linesman splice) and solder. Once you've soldered, leave it to cool for a couple seconds, slide the small heatshrink over the joint you just made, and heat it up. You should have something that looks like this:

For those who are a little less confident with a soldering iron or wire splicing, I recommend buying something like this and referring to the USB-A cable pinout here.

Flash your Pro Micro with a regular cable first and then try plugging in the cable attached to the PCB and your new 4p4c-USB cable in the 4p4c port. If it works, great! If not, you'll need to recheck your wiring.

For M0110 Only

Follow all the cabling instructions as above. If you look at the first diagram on this post, you'll see the pinout for the loose pins of the 4p4c connector. As this is a one sided PCB, there's nowhere to solder the 4p4c connector in, so we'll have to get a little inventive. Thread your micro-end USB wires through the respective J holes on the non-solder side of the PCB (making sure to use J2 for the ground wire) and solder them down to the pads on the back of the PCB. Next, strip your kynar wires and solder one end to each of the solder joints you just made for the USB wires.

You'll see some small holes next to each J hole that have no pad on either side. These were added in the final production run to make it easier to route this kynar wire to the pins on the 4p4c connector. Thread your wires through these holes and then cut to size and strip the other end.

This is the hardest bit - put a small dab of solder on each pin of the 4p4c connector, then let it cool - then heat it up again and push the kynar wire into it. Once you've done this, you should have a connection from each pin on the micro side of your USB cable to the pins on the 4p4c connector, and you can continue to follow the rest of the cabling guide.

Hello, I am insane and recently purchased four Olympia Carrera typewriters. Now, you get to benefit from my idiocy.

Marquardt Series 6180

This series of switch is basically previously undocumented, and was thought to be very rare. The latter part is pretty much completely untrue. Let's get properly into it.

Variants
There are two variants of this switch - and I can confirm that in this post. What's more, they have significant internal differences. Firstly though, let's look at the commonalities. Both switches share the same bottom housing, including integrated diode, and contact module. They also share a similar method of action - i.e. that the slider makes contact with a separate part, which then puts pressure on the contact module. Past this is where the differences begin.

Brown top variant (Marquardt Series 6180 Brown? Mint Green?)
This is the earliest version of the switch I've found - in an Olympia Carrera manufactured at least before 1986. It has a dark brown top housing, and a slightly mint green slider. The slider is MX mount, and slides past a semi-free-floating contoured plastic rocker (it merely rests in a recess in the top housing) with a peg on the other side. This peg is what puts pressure on the contact module, closing the circuit. The switch weighting is in the ballpark of MX Black, and has 4mm travel. When fully depressed, the slider is completely inside the housing.

Black top variant (Marquardt Series 6180 Black? White?
This variant of the switch was found in a 1988 manufactured Olympia Carrera. It has a completely black top housing and white slider. The slider remains MX mount, but is slightly taller than the brown variant and has a notch, and instead of a plastic rocker, it slides past a uniquely shaped leaf spring, which rests in a slit in the top housing. It has a prong which puts the pressure on the contact module. This switch is significantly heavier (through unscientific measurement, I put this somewhere in the range of 10-20gf heavier - I believe this to be a combination of a stiffer return spring and weight from the leaf spring). It still has 4mm travel, but the slider is slightly outside of the housing at bottom-out. It should be noted that the difference between the plastic rocker and the leaf spring makes the black and brown top housings two-way incompatible with each other.

Sources
These switches can be found in Olympia Carrera typewriters, which are exceedingly common. Note that this is the Carrera only, as far as I am aware - Carrera Si, De Luxe, etc need not apply. However, more than one instance of this typewriter I have bought has come with Cherry MX Olympia Linear Clear switches, so your mileage may vary.

Takeaways
Pretty much everything the community knew about this switch was wrong. It is legitimately a series, consisting of at least two variants (and possibly more - there are two keyboard part numbers for Carrera typewriters I am still unaware of). They are nice switches that can be had for pretty cheap, and given that Carreras came with covers, are fairly likely to be in good condition.

A faithful re-creation of the M0110A PCB, with some nice QoL features, reasonably accurate markings and a silly cable system to preserve the external appearance of the keyboard.

Features

• Supports Alps SKCC and Mitsumi Standard models
• Supports Pro Micro or Pi Pico as MCU
• Preserves keyboard appearance with some smart cable chopping and re-use of the original 4p4c connector
• N-Key Rollover - through-hole or surface-mount diodes
• Supports ANSI mod (ANSI backslash, 2.25u right shift)
• QMK and VIA firmware (Pro Micro only for now, Pi Pico will use KMK until QMK is ported)

Why is this PCB needed? What's good about it?

The M0110A (and indeed, all compact Apple keyboards) shipped with hard 2-key rollover. This means that you can't press more than two keys on the keyboard, excluding modifiers, at the same time. This can lead to dropped keystrokes when typing at speed. Other attempts at solving this problem exist, but most of them don't support the Mitsumi variant of the M0110A, which is the more common variety. This PCB delivers N-Key rollover to both common variants of the M0110A, alongside dynamic keymaps and macro support.

Every effort has been made to make this PCB blend in as much as possible with the keyboard, from accurate silkscreen, to a system to make use of the original connector over USB.

Where and when can I buy this?
Group buy details will be announced soon. PCB is currently undergoing a small private beta, and documentation being produced.

https://wiki.keyboard.institute/doku.php?id=guides:waxboil

The real "pingmaster." Alps SKCC Tall Cream switches. Quite stiff but super smooth.

Not much done to this board, came with a really dirty case that took about half an hour to scrub up, and I brushed out the plate. Fixed a non-actuating switch on the 'L' key and removed the locking lug on the SKCC Lock switch on caps lock so I could use it as ctrl (which is actually quite painful it's a very heavy switch).

It's a nice board overall, but quite tiring to use for extended periods.

The White Whale! Acquired from eBay in nearly perfect condition, this keyboard only needed a quick wipe down of the PCB with isopropyl alcohol to be in good working order. Converted with a self-assembled TH-XWhatsit controller. Added a solenoid to give this the oomph it was denied by IBM.

EDIT: Picked up a very cheap Selectric II, and now this has Selectric caps on most of the alphas, and is wearing a cool black IBM badge.

Magnavox Videowriter keyboard rebuilt from parts. I received the parts in addition to the Alps SKCM Brown switches that went into my AEK alps64 build.

This keyboard previously used restored Alps SKCM Blue "piss blues" (i.e., they were harvested from a board that smelled like cat urine), but I ended up liking the form factor so much that I decided to get some more interesting switches in better condition.

On to the Videowriter! The case and caps were in fantastic condition, so I couldn't pass up the chance to rebuild this nice compact board.

The switches used for the final form of this rebuild are Alps SKCM Amber, the slightly heavier, more tactile, and louder cousin to blue Alps:

The SKCL Compact switches and caps were not provided, so the ones that ended up in the keyboard are from a Sharp PA-1000.

The PCB was not in such a good shape, and also needed a controller replacement to work over USB - for this I used a Teensy++ running QMK. This started out fairly neat, and you can see the neat aspects of this replacement from the front of the PCB.

I then fixed a few traces between switches that were broken due to lifted pads. However, things didn't work right off the bat. Keys in row 6 (D, F, G, H, J, K, L, ;) were also registering presses in row 7 (X, C, V, B, N, M etc). During troubleshooting, I lifted a fair few pads around the controller, so these had to be rewired by hand. Additionally, I couldn't find the short between rows 6 and 7 with any amount of tracing, so I ended up disconnecting row 6 from the PCB and handwiring it:

Finally, the stabilizers, and especially the 9U(!) spacebar were impressively rattly, so I lubricated the stabilizers with Threebond silicone grease. This didn't impact the hollow sound from the spacebar though, so I filled the inside of the keycap with neoprene to dampen that somewhat.

Everything works now and it's a delightful little board.

UPDATED 9/12/2020

A work in progress. This keyboard module was removed from a Sharp ZX-510 typewriter. The keycaps are thick doubleshots and it uses Alps SKFF (vertical plate spring) switches, which are pretty hard to find:

The module had several metal parts to keep it secure in the typewriter. With some finagling, it was possible to rearrange and discard some of these to create a decent typing profile:

I plan to handwire this board and make a case for it around the metal skeleton using plywood and possibly acrylic sheets. Updates to come!

Update #1:

This is now converted (no handwire!) and working over USB. There are still some kinks to work out, like shift lock not working, and a total lack of LEDs, but it is a working keyboard.

As I've done for the Data General, here's the matrix for this thing if you ever come across it:

Remaining work to do:

• Enable in-key LEDs and shift lock
• Enable LED bank, top switch and button board
• Figure out how to drive VFD or replace it with a similar LCD
• Case

The original AEK and the best chassis Apple ever made, in my opinion. This one has Alps SKCM Orange switches and originally came with a chipped case and several switches not working:

A number of switches had dry solder joints, and others had non-functional switchplates. I replaced the non-functional switchplates and reflowed the solder joints. I then purchased a replacement case and retrobrited that.

Apple Desktop Bus Keyboard (Part no. 658-4081) with Alps SKCM Orange switches. Keycaps cleaned with denture tablets, case scuffs cleaned with a magic eraser, retrobrited with Indola 40vol cream developer indoors, and switches disassembled and top housings cleaned with an ultrasonic cleaner.

Restored and modded Apple Standard Keyboard, with Alps SKCM Salmon switches. These have been modified (the original tactile leaves have been replaced with the click leaves from alps.tw Type OA2 clones, sourced from a Focus FK-2001), and the stabilisers have been lubed with silicone grease. The ADB protocol conversion is achieved with a Teensy 2.0 running hasu's tmk_keyboard firmware, using the original coiled ADB cable.

The exterior was retrobrited with Indola 40vol cream developer in an indoor UV-led powered retrobriting tub. The switch housings have been ultrasonically cleaned, and the plate brushed down.

A quick and cheap build in order to use up a damaged Apple Extended Keyboard II, using hasu's wonderful alps64 PCB and plate. The Alps SKCM Cream Damped switches from the Apple Extended Keyboard II have had the rubber dampeners removed, and have been lubed with Weldtite TF2 PTFE lubricant to reduce rattle from the low-profile case. The Alps SKCL Lock switch for the caps lock key has also been retained. Stabilisers have been lubed with silicone grease for the same reason.

iPod 3rd generation purchased as "not working". Was in working order when connected to a FireWire port and charged, but the battery needed to be replaced. Once this was done, front and back case were cleaned and then buffed with Autosol metal polish.

Chicony KB-5182 with SMK 2nd Generation "Monterey" switches. Keycaps mostly (except for enter) replaced with new old stock doubleshots, case cleaned with a magic eraser and retrobrited with Indola 40vol cream developer indoors.