IBM PC Model F keyboard – Type 1 vs Type 2
Here are some pictures of an early IBM PC 83 key keyboard known as the Model F. This was the keyboard used with the IBM 5150 PC and the IBM 5160 PC XT computers. The earliest of IBM 5150 PC keyboards were slightly different, hence there are two types of IBM PC keyboards. The one most commonly found is the Type 2. The Type 1 keyboard has different internal electronics with an extra RESET pin activated. The regular Type 2 keyboard does not have that pin connected and does the keyboard reset internally when powered on. Both, however, use IBM’s “XT” protocol for communication.
While the Type 1 keyboard appears to always have a metal keyboard connector that mates with the IBM PC, not all IBM PC keyboards with a metal connector are Type 1. The only true way of determining if an IBM PC keyboard is type 1 is by opening it and checking for the elongated internal PCB with the extra electronics.
Here are some pics:
For comparison, here are a couple of pictures of the Type 1 (top) and Type 2 (bottom) keyboards. I have also added a picture of the keyboard controller chip and internal markings for date codes on the Type 2 keyboard used for comparison.
