Full Details

Name and Model Number Jacob Zedak's Rav-Bo Computer
Country of Origin Mandatorial Palestine
Date of Manufacture ~1942
Front Scales C [D B K L Sin Tg Small-angle Sin+Tg]
Back Scales  
Scale Length 43 cm
Type of Rule Disc
Construction Paper scales over plywood stator and rotor, celluloid cursor
Area of Use Generic
Comment See details at https://www.nzeldes.com/HOC/Zedak.htm
Rarity RRR
Donor Collection of Nathan Zeldes
Match Number 412
(Click Picture for Details)

In conjunction with our 'donors' we assign a rarity rating to each item, based on the system devised by Herman van Herwijnen
(1929 - 2004), renowned Dutch collector, author, and creator of Herman's Archive, a collection of 5,000 slide rule images on CD.
• RR = Rare - 1 of 25 collectors has one; it may take a year to find an example in the marketplace.
• RRR = Very Rare - only a few known to collectors; may be several years before it comes up for sale.
• RRRR = Extremely Rare - a museum piece; unlikely that an example will come up for sale.