Nabu KBD-2

Nabu KBD-2
Switch	Alps SKCC Cream
Sense method	Contact
Protocol	Serial (RS422)
Keycaps	Doubleshot ABS

The Nabu KBD-2 keyboard was bundled with the Nabu Personal Computer System; a personal home computer system that was capable of downloading software and information content over cable TV.

The keyboard bears a distinctive charcoal colour and “Nabu Personal Computer” sticker in the top right corner next to various function stickers. The series, as far as is known, shares the same construction. The keyboard was bundled with the Nabu Personal Computer System. The keyboard uses Alps SKCC cream switches, with a latching switch located below the Caps Lock key. A 6 pin DIN connector is used to connect to the Nabu PC, with 2 additional DB9 ports located on the rear of the keyboard for optional joysticks.

The keyboard case is a two piece, injection molded plastic shell that is held together by five counterbore screws with washers, and one countersunk screw. The screws are screwed directly into the top case. Within the housing assembly, a further 4 screws at the distal left and right of the keyboard are used to secure the metal switch mounting plate to the top housing. The bottom case has a label indicating the batch, revision, and serial number of the keyboard.

A SKCC Lock switch is present on the “CAPS” key. The SKCC Cream switches are infilled with a sort of resin or glue in the switch terminal recess. They are the black switchplate variant, likely manufactured around 1982 using IC dating.

The switches are soldered to a PCB and clipped into a painted black steel plate on one side. The switch-plate assembly is then secured to the bottom half of the case with double-sided foam tape. The adhesive from the tape corrodes the steel plate over time, and the corrosion is present on NOS (new old stock) units. There are four slots for screws present on the plate; however, these are not used in the keyboard.

The PCB is connected to the controller board through a ribbon cable that is soldered in. The controller on the keyboard is a Motorola MC6803P.

There is a female DIN-6 connector present on the back side of the keyboard labeled “TO COMPUTER,” along with two DB-9 joystick ports labeled “CONTROLLER” with a number below each port. All of the ports are soldered onto the controller board. Pins one and six are unused on the DIN-6, pins two and three for power, and pins four and five for data. The shield is connected to ground.

The keyboard is 2KRO, and repeats keys when they are held down continuously. However, special keys do not autorepeat, such as the arrow keys. They instead only send one signal when depressed or released.

The keycaps are manufactured by Alps Electric in a distinctive spherical sculpt. All keycaps are doubleshot ABS, with the majority being white on black. The “Pause”, “TV” and “Go” keys are red, yellow and blue on black doubleshots, respectively. All keycaps are textured at the top with smooth sides.