This thing is very strange. It's fully mechanical, all Cherry Browns, but doesn't have n-key rollover. Actually messing around at first I thought it had one-key blocking on every combination of keys excluding the Shift/Fn modifier, but no. It buffers inputs, onboard.
If I tap 1, it sends a scancode for 1. If I hold it, it repeats normally.
If I hold 1 and then tap 2, it sends a scancode for 1, does nothing until I release 1, and then the scancode for 2 is sent.
If I hold 1, then tap 2, and then tap 3, it sends the scancode for 1, and then when I release 1, it ignores the 2 but sends the scancode for 3.
If I hold 1, then tap 2, and then tap 3, AND THEN TAP 2 AGAIN, it sends the scancode for 1, then on release of 1, it ignores the first 2, sends the scancode for 3, and then also the scancode for the second 2.
1 (2-3-2-3) results in 133.
1 (2-3-3-2) results in 132.
1 (2-3-3-2-2) results in 1322.
1 (2-3-4-5) results in 15.
1 (2-3-4-5-4) results in 154.
1 (2-3-4-5-2-3-4-5) results in 15.
1 (2-2-2-2) results in 12222.
1 (2-3-2) results in 132, the repeated character is ignored the first time, but 1 (Shift/Fn (2-3-2)) results in 1@#@ - nothing is ignored.
What is it doing? Why is it like this? Is this somehow related to the calculator-like MC/MR/MS/M+ functions?