The step peek involves collapsing a break into a step. This basic action was described in the anonymous Asti Manuscript, c. 1700, p. 106 of the Pieper translation. This manuscript was translated in Gibecière, Vol.8 No.1, Winter 2013, p. 29-234. Arthur Buckley described using the technique to glimpse a riffle-peeked selection in Card Control, 1946, p. 34. Buckley ascribes no source for it.
Jean Eugène Robert-Houdin described a related, ancestral peek with the translated title of “The Card Seen by a Glance” in Les Trickeries des Grecs Dévoilées, 1861, p. 176 of the Hoffmann translation.