This keyboard was OEMed for Corona Data Systems.
This keyboard is an XT keyboard that was designed for luggable computers. This keyboard technically falls under the NMB First Generation series of keyboards but was OEMed for Corona Data Systems as they manufactured luggable computers for many different companies such as Philips.
Switches
Keycaps
Upper Case
Mounting Plate
PCB
Back Plate
Cable
The keycaps are made out of PBT with dye-sublimated legends. These keycaps are pressure fitted as they lack the clips that can be found on all keycaps after the First Generation of NMB keyboards.
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.
The backplate consists of a single plate with a V-shaped trough that is offset from the top edge of the upper case and runs laterally parallel to the top edge. The backplate is black. Early models of the first generation keyboards contain a steel backplate where later models used plastic for the backplate. Note that earlier models contain a grounding screw in the back plate where later models do not.
The switch plate is made out of stamped steel. The plate has deeper stamping around the switches so that the entire switch plate could be produced with less material. The plate is only coated with a clear coat.
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.
The cable is a coiled RJ11 cable that is 6P6C. It can stretch up to 1 meter.
Top
Model # / Jumpers
Top
Copyright
Bottom
Part NO
Bottom
PCB Markings
Source: https://books.google.ca/books?id=mt9tF7XMFX4C&lpg=PA346&pg=PA346