> Input: ... gameport joystick via BIOS INT 15h with auto-calibration

Joystick calibration: what a blast from the past! Blast from the past I encountered recently...

Joysticks had to be "calibrated" and it was something you had to do for each game that supported joysticks. These would give back analog values and they'd depend on the phases of the moon or the room temperature or both. I'm not making this up: this was a serious pain point both for players and coders.

FWIW in that DOS game of mine from 1991 or so for which I still had the .ASM source code files (about 30 000 lines of assembly code, 15 000 of which were auto-generated code to do very fast sprites drawing in the VGA 320x200 "tweaked" mode) and which I managed, at long last, to get to compile again a few days ago thanks to UASM (and quite some LLM help), I found lines like these:

    ul_corner_ch:
        db      63,"PUT YOUR JOYSTICK IN THE UPPER LEFT CORNER AND PRESS A BUTTON  "
    lr_corner_ch:
        db      63,"PUT YOUR JOYSTICK IN THE LOWER RIGHT CORNER AND PRESS A BUTTON "
    p1_choose:
        dw      1       ;1 keyboard   2 joystick
    p2_choose:
        dw      0       ;0 none       1 keyboard   2 joystick

And basically a 350 lines assembly file only for joystick calibration.

So you can understand that "auto-calibration" as in TFA is quite a selling point!