Quoting: mix1
but, when I install Synaptic Booster (+5 Knowledge) (or other knowledge cyberware), I see 13/19 in the Learn New Skill menu, as it was before, despite
the Knowledge stat is increased from 12 to 17.
Used GearHead version is 1.100.
What is wrong?
GH1 tracks two different values for each of your stats -- an underlying base value and a current value. The current value fluctuates with temporary conditions, like morale, hunger, and some statuses. You can recognize the base value since it's the level at which the stat number is dark green. When the current level is higher than base, the number is light green, and when the current level is lower than base, it is red.
Cyberware is accounted in GH1 like a temporary condition, and in GH1 the skill limit depends on your base stat. So Cyberware cannot count towards your skill limit, although it does make Knowledge-based skill rolls better.
It wouldn't be too hard to hack GH1 to use the current stat for calculating the skill limit. You'd just change "PC^.STat[ STAT_Knowledge ]" to "CStat(PC,STAT_Knowledge)" in the function NumberOfSkillSlots() in file ghchar.pp.
But I don't think this is a good idea, because that would make the Skill Slot number fluctuate with your morale. The present code only makes sense under the assumption that the Knowledge stat used may rise but will never fall.
Even if we defined a "CyStat(PC,stat)" function that counted cyberware but not anything else, Knowledge could still drop if the player installs Kn-hurting cyberware, or swaps in cyberware with a lower Kn bonus.
(Although the assumption is already violated in the official version in one place. GARU serum reduces your base Knowledge.)