The GM852P was a low profile parallel version of the GM827. The only differences were that it was also available as a serial version (GM852S) and that the very latest versions extended the function keys into the control mode as well.
It was made available in several different languages. The GM852P could be used with both the IVC and SVC cards, the GM852S only with the SVC.
The serial version sent the same codes as the parallel version, but one bit at a time. The output consisted of a clock line and a data line. This is similar to the PS/2 keyboards in some ways, but the lines were normally low, whereas the PS/2 has them high.
The thing that makes this really different from PS/2 keyboards is that the latter only sends “scan codes”. These are codes that relate to the mechanical position of the keys on the keyboard, not to the characters that they produce. Translation to the required characters is done in software within the PC. The Gemini keyboard sends codes for the actual character so the Gemini card has no need to translate.
Links on the SVC card allow the system to be switched between single (GM821) and double byte (GM827, GM852P) keyboards. The double-byte system is necessary to get the extra codes to handle the function keys.
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