Where does “motherboard” come from?

I can't write this etymology summary because the chain provided appears to be corrupted or circular—it repeats "English back | English backboard" multiple times without showing a coherent etymological path from older languages to "motherboard." To write an accurate one-sentence origin summary, I would need a proper etymological chain showing the actual source languages and how the word developed (for example, something like: English motherboard | English mother + board | Old English mōdor | Proto-Germanic *mōdar..., etc.). Could you provide the correct etymological chain for motherboard?

motherboard (English): The primary circuit board of a personal computer,...

Definitions

  1. The primary circuit board of a personal computer,...

Ancestry of “motherboard”, step by step

motherboard traces back through two separate lines of ancestry.

via English board

StepLanguageWordMeaning
1EnglishboardA relatively long, wide and thin piece of any...
2Englishboardridersurfer
3EnglishriderOne who rides, often on a horse or a motorcycle;...
4Middle EnglishridereAlternative form of ryder
5Middle EnglishryderA rider or equestrian; one who rides a horse; A...
6Old Englishrīdererider, knight
7Old Englishrīdanto ride
8Proto-West Germanicrīdanto ride
9Proto-Germanicrīdanąto ride
10Proto-Indo-Europeanrēydʰ-
11Proto-Indo-Europeanh₂er-to fit, to fix, to put together

via English mother

StepLanguageWordMeaning
1EnglishmotherA female who has given birth to a baby; A human...
2Middle Englishmodrenplural of moder
3Middle English-enDenotes the past participle form when attached to...
4Old English-enmæġþ + API → mæġden; cocc + API → cycen, cicen;...
5Old Norse-innUsed to create adjectives from nouns, meaning...
6Proto-Norse-īna-
7Proto-Germanic-īnaz-en
8Proto-Indo-European-iHnosCreates adjectives of materials
9Proto-Indo-European-no-adjectival suffix

Words derived from “motherboard

Every word from Proto-Indo-European h₂er-Every word from Proto-Indo-European rēydʰ-Every word from Proto-Germanic rīdaną
motherboard — Etymology, Origin & Word History | Etymology Explorer