Argh. You have no idea how many databooks and catalogs I went through to find that 9034--and then was perplexed as to why anyone would carry a mask-programmed ROM as a generic part. Sigh. At any rate, there were a lot of manufacturers making DTL that we don't think of today. In particular, Philco: 9093 = 853 9094 = 856 9097 = 855 9099 = 852 9930 = 830 9931 = 831, etc. 800-series is the lower-cost "commercial" grade of 900-series logic with a narrower temp range, also available in plastic DIP. The confusing thing about DTL part numbers is how they're "shoehorned" within the RTL part number scheme. So, a 928 is RTL, but a 930 is DTL; A similar situation exists with the 9000 numbers. 9931 is DTL, 9989 is RTL. A point of curiosity that I have is what was the highest level of integration achieved before DTL was relegated to the "obsolescent" bin? I have a couple of Fairchild addressable 8-bit memories; was there anything more elaborate? A full adder, perhaps? Cheers, Chuck