I bought a couple of keypads of Ebay some time ago and since they were so nice, I decided to use them in my latest project. Since there are no data sheets for this, that I could find, I checked the wiring myself. The unit is from Bally systems, made by ACT and has P/N 105123D
Here are a couple of images of the unit.
And here’s a connection table. Keep in mind that the connections range in resistances from 30 to 100 Ohms.
| Pin 1 | Pin 2 | Pin 3 | |
| Pin 4 | CLR | 0 | ENT |
| Pin 5 | 3 | 6 | 9 |
| Pin 6 | 2 | 5 | 8 |
| Pin 7 | 1 | 4 | 7 |