Oriental Tech OK-100 series
|This article requires additional photographic illustration — needs photos of other variants|
|Keyswitches||Oriental Tech spring-over-membrane|
|Keycaps||Cylindrical Alps-mount double-shot|
|Introduced||1991 (FCC registration)|
OK-100 is a series of progressive-rate spring-over-membrane keyboards from Oriental Tech Co Ltd of Taiwan.
To cater for both ANSI and ISO, one (ANSI) or two (ISO) slider shafts are located in a separate module; the underlying membrane has three contact positions accordingly.
According to the box, the OK-100 series was sold in the following layouts: Arabic, Belgian, Canadian, Chinese, Danish, Dutch, French, German, USSR, Italian, Korean, Latin America, Norwegian, Portuguese, Spanish, Swedish, Swiss, UK and US.
The keyboard characteristics vary; the following characteristics have been noted on one OK-100M keyboard, and they may not apply to all keyboards:
Various switches use longer return springs, to give them more resistance. These include keys such as control and shift — generally, keys around the side and bottom edges. Broadly, these use blue sliders instead of white sliders, but slider colour does not appear to be completely consistent.
The OK-100M leaflet claims 60±20 cN for standard keys, and 90±25 cN for the space bar, with an initial force of 30 cN. The actual feel of the switches is significantly lighter than 60 cN, with a simple coin-stacking test suggesting around 45 cN for the normal keys. One could also presume that all the other heavy keys use the same nominal 90±25 cN switches as space bar.
Different membrane springs
The same keyboard can have both parallel (cylindrical) and flared membrane springs (the springs inside the sliders that press down on the membrane sheets). No reason for this is apparent.
The following models are referenced on the box:
|Model||Confirmed to exist|
|OK-100M||Confirmed by box|
Sticking key; for a NIB keyboard, this indicates a manufacturing defect