Second Generation

Overview

After the first generation of PC-compatible keyboards that was primarily produced for companies such as Tava, Tandon, and Tandy. NMB moved on to the second generation of keyboards, NMB produced more unbranded keyboards that were popular with many different PC clones. Some second-generation keyboards can be found with a simple sticker that displays the company logo that it was produced for on the upper case.

The second generation of NMB Hi-Tek 725 series keyboards have the following seven main components introduced:

  • Switches

  • Keycaps

  • Upper Case

  • Mounting Plate

  • PCB

  • Back Plate

  • Cable

Switches

The second generation of keyboards used the following variants of switches below.

Early keyboards used the round one eye and square one eye switches that were introduced in the first generation of NMB keyboards. Switches can be found in two main types linear and tactile. This is the first time that NMB introduced a new type of switches which was the tactile and clicky variant. Switches on these keyboards were tactile including LED switches but excluding spacebar switches that were still linear.


Later keyboards used two eye switches that were introduced in this generation. The later switches can be found both in linear, tactile, and clicky variants. NMB also introduced their later famous different colored spacebar switch. This was the first time that NMB also somewhat moved away from the colored dot on the spacebar switch but not completely.

Early Switches

Later Switches

Keycaps

The keycaps are made out of PBT with dye-sublimated legends. The keycaps for the second generation include clips on the sides of the keycaps to secure them properly to the switch.

Keycaps for second-generation keyboards can be used on all generations of NMB keyboards including the first generation due to the sidebars of the keycaps being the same thickness as first-generation keycaps. The keycaps in this generation have the same shiny sides as the first generation.


Upper 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.

XT models contain additional features in the lower case including a speaker grill in the center of the keyboard case along the top edge of the lower case. Additionally, XT models also have the option for a mouse to be plugged into the left side jack of the keyboard for keyboards that used RJ-11 jacks.


Lower Case

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.

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.


PCB

The PCB is a double-sided PCB with all traces on the backside of the PCB. The controllers found on the PCB vary, some later models have been found with both Toshiba and Mitsubishi controllers.


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.


5 Pin Din

The cable contains a molded block that is press-fitted into the upper case to keep the cable secure.


RJ-11

The coiled cable is normally 30 centimetres long with RJ connectors on either end. Keyboards that use the RJ-11 cable have an RJ-11 female jack in place of the molded block that would have used for the 5 pin din cable.

Variants

XT

Top

PCB

RJ

Switches

Back

Internals

Switches

Credit: Engicoder

AT

Top

Bottom

Top

PCB

Switches

Bottom

Internals

Credit: Engicoder