Third Generation

Under Construction 

Switches

Keycaps

The keycaps are made out of PBT with dye-sublimated legends. The keycaps within the Third Generation has changed three times throughout the duration of the Third Generation of NMB keyboards.

The keycaps on generation third boards contain rod stabs similar to IBM stab rods.

This generation introduced is the IBM like sublegends on the number pad of this generation of keyboards. Throughout the generation the keycaps have change numerous times.

There are three different versions of keycaps within the Third Generation of keyboards:

Early

Early keyboards starting in 1987 the keycaps contained the same thick fingers on the keycaps that interact with the locating slots on the switch slider. These keycaps still carry over the same shiny sides of the keycaps like the Second Generation of NMB keyboards.

The keycaps in early NMB keyboards contain rod like stabilizers. These stabilizers are similar to the IBM Model G Keyboard. The implementation of these rod based stabilizers however, were not as well implemented like in the IBM Model G. The stabilized key rod interacts with a dummy switch that has a round well for the rod to side into. This ensures that the stabilized key still has the same weighting as all other keys. 

Middle

The keycaps in keyboards after 1987 do not contain the thicker fingers and the fingers are thinner near the edges of the keycaps. The keycaps are still shiny on the sides. Some stabilized keycaps have transitioned from the rod stabs to wire stabs. Sometimes certain keyboards can contain a mix of both, this is due to the slow change of molds as they wore out. 

Late

The keycaps in later Third Generation of keyboards have matte sides rather than shiny. The fingers in the caps have not changed even though the side texture has. 

Upper Case

The upper case is made out of a single piece of beige ABS plastic. The plastic is textured due to the molding process that is used to create the upper case. 

There are two versions of the upper case: 

Early

Early cases have rectangular tabs on the chin of the keyboard these lock into the bottom of the keyboard via the bottom case. The tabs lock into the the bottom case in the keyboard chin so that the two halves of the keyboard case hinge together. Then the four tabs that extend from the back of the keyboard forehead lock into the bottom case completing the keyboard. Depending on the mold that was used to create the upper case some upper cases will not have mold markings. This indicates that the upper case is very early and that only later cases after the second mold contained mold markings including the production date of the case. Later early cases have the additional screw holes where early top cases do not have the screw holes drilled.

Later

Later cases have three fingers in parallel that replace the rectangular tabs. These three fingers seem to follow the same ideology that three fingers were used for redundancy reasoning. If the user breaks one finger that the other two would still be usable. The finger based tabs lock into the the bottom case in the keyboard chin so that the two halves of the keyboard case hinge together. Then the four tabs that extend from the back of the keyboard forehead lock into the bottom case completing the keyboard.

Lower Case

The lower case is molded from the same ABS plastic as the upper case. A set of slots are located in the lower case that joins the two halves together. The feet that are integrated into the lower case are flush with the lower case when retracted.

There are two versions of the bottom case depending on how early the case was created.

Switch Plate

The switch plate is made out of stamped steel. The plate is bent on either so that it can be mounted to the upper case. The plate is painted with a thin layer of black paint. The paint is then protected by a thin layer of oil to prevent rust.

There are three versions of the plate:

LED Early Stabs(Early)

This switch plate contains holes for both LED switches and pole based stabilizers. There is extra space for the plate mounted stabs around the right-hand shift key. LED based plates have LED switches in the "Caps Lock", "Scroll Lock" and "Num Lock" positions and the LED switches are south facing.

LED(Early)

This switch plate contains holes for LED switches. LED based plates have LED switches in the "Caps Lock", "Scroll Lock" and "Num Lock" positions The LED switches are south facing. 

NON LED(Late)

This switch plate does not have cutouts for LED switches in the "Caps Lock", "Scroll Lock" "Scroll Lock" and "Num Lock" positions therefore the switches are slight offset.

PCB

The PCB is a double-sided PCB with all traces on the backside of the PCB. The PCB always has diodes for each switch as N Key rollover was a selling point of the RT-101 keyboard.

Early Stabilizers

Early LED

This version of the PCB contains 

Middle

Late

Cable

The cable is approximately 1 meter long for the coiled variant and stretches up to 2 meters easily. It contains a molded 5 pin din connector with 6 pin headers using a molex connector on the PCB.

Variants

BAE

ISO

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