The Summa Logicae (Latin, in English it's the Sum of Logic) is a textbook on logic by William of Ockham. There are articles about the Summa Logicae in Wikipedia and in Logicmuseum.
It was published in Paris in 1488. There are different typed variants of this textbook, for example here (in English).
But I can't find any scans or photos of the original handmade manuscript or the original (first) edition. Do you know any links or libraries or museims, where I can find it?
According to WorldCat, the 1323 manuscript of the Summa Logicae is held at the Vatican Library, whilst a microfilm of that manuscript is held by the Saint Louis University library system; WorldCat doesn't bring up anything else for the 1323 manuscript (though Saint Louis University also seems to have microfilms of a number of other 14th century manuscripts of the Summa Logicae), and no facsimiles of the 1488 editio princeps (held at the Bavarian State Library, according to WorldCat).