[1letterunixname]

Square pixel 360×240 was sane, but 360×480 always felt dirty.

IIRC, Mode X video mode set routines boiled down to an exhaustive table of VGA register control values. (See SDL or older FreeBSD for examples.) Then, the fun was pixel addressing, bitblting, and page flipping.

[p1mrx]

> Square pixel 360×240

Did you mean 320×240?

[1letterunixname]

Yes, Google. ;@P Thanks.

360x270 wouldn't be possible with VGA.

4:3 pixel aspect ratios of mode X-like VGA modes

    256×256: 1.0     (Stretched)

    320×200: 1.6     (Mode 13h - slightly squished)
    320×224: 1.428.. (Imperceptibly squished) 
    320×240: 1.333.. (Square)
    320×350: 0.914.. (Stretched)
    320×400: 0.8     (Stretched)
    320×480: 0.666.. (Extremely stretched)

    360×200: 1.8     (Very squished) 
    360×240: 1.5     (Imperceptibly squished except when drawing circles)
    (360×270 is impossible)
    360×350: 1.029.. (Slightly stretched)
    360×400: 0.9     (Stretched)
    360×480: 0.75    (Extremely stretched)

    400×300: 1.333.. (Square)

[Dwedit]

360x240 and 360x480 are both real modes.

But it was 320x240 that had the square pixels.