| Attachment | Size |
|---|---|
 Rafi keyboard 1976 | 1.63 MB |
| Rafi keyboard 1976 number | 1.39 MB |
Hi,
I have a keyboard used in a german made accounting computer from 1976. The keyboard has possibly hall-effect sensors to recognize key presses. Im interested if anyone has seen a similar keyboard? Maybe it can be adapted to the Apple 1?
From what I've read if it uses a strobed parallel ASCII output it can be made to work. Made to work does not necessarily imply "plug right in". Most likely some kind of adapter cable will need to be made at minimum, and it is possible that some additional logic like inverting signals, etc, may be required to make ti work. If you've got any kind of specs on the output that will make it easier. If not you'll need to figure out what the output is in order to figure out what is necessary to make it work on an Apple 1.
[quote=softwarejanitor]
From what I've read if it uses a strobed parallel ASCII output it can be made to work. Made to work does not necessarily imply "plug right in". Most likely some kind of adapter cable will need to be made at minimum, and it is possible that some additional logic like inverting signals, etc, may be required to make ti work. If you've got any kind of specs on the output that will make it easier. If not you'll need to figure out what the output is in order to figure out what is necessary to make it work on an Apple 1.
[/quote]
There is a 256x8 rom (1702 compatible) that may be used for keycode conversion.
-Jonas
This keyboard is extremely rare. RAFI made at least two keyboard types like that (with the castellated alignment rails): the older unnamed series offered magnetoresistive and mechanical switches (patents filed in 1970), which was followed by Rafi-System 72, or RC 72 series, which was Hall effect and mechanical (introduced in 1973 it seems). I am not aware of anyone ever finding the older type, and I have only ever seen one example of RC 72, using newer switches with much smaller magnets than the design in the patent and the 1983 catalogue.
The pinout of the switches may help identify what’s what: I am guessing two terminals for mechanical, while magnetoresistive has three and Hall effect has four (for non-illuminated switches). The 5 code on the PCB is probably the PCB part; keyboards have 3 codes instead, and I don’t see such a code, as that code would also indicate the series.
IMG_1276.png
IMG_1277.png
IMG_1278.png
Oops, somehow I never got notified that you posted these photos. Thanks. Indeed, that’s RC 72 C, Hall effect.
In terms of conversion: the first step is to look at the external connection (header, edge connector etc) and see where all the PCB tracks go, and identify VCC, GND, strobe, and the data lines. At the moment, the photos don’t show the full circuit. To be clear though, are you considering attempting to trace the circuit, or just hoping that someone has the schematics? Generally, keyboards of this area all tended to work the same, but you have to identify the connections and whether positive or negative logic was used. (MOS/LSI-encoded keyboards would often also require −12 V, but I am guessing yours is pure TTL.)