[saagarjha]

> The mistake was representing it as anything other than an 8-bit number because that's what the hardware really would have done.

I would be significantly more pleased if this was the documented, intended behavior that was being emulated intentionally, since the previous choice leaves me a bit worried that this is just an instance of “hey we can just use this type as a convenient index that doesn’t go out of bounds”.

[EvanAnderson]

The sibling comment to yours has a link to such documentation, and a link to a really nice discussion re: reverse engineering this behavior on various clone VGA chipsets. The IBM RAMDAC documentation is pretty authoritative, IMO.