ハードワイヤード

ハードワイヤードというと変更不可能という印象があるけど、本物のワイヤラッピング時代では手作業で配線を変更して命令を追加できたりしたらしい。

• http://its.victor.se/mailman/private/its-hackers_its.victor.se/2023/000955.html

Since the PDP-10 instruction set was hard-wired, a simple wirewrap tool could be used to change how instructions worked. And was. I recall that the MIT-AI machine (maybe others too) acquired a new ROT (rotate) instruction that rotated "the other way", i.e., clockwise versus counterclockwise. That was somehow useful in the Chess program.