In anticipation of Chapter 4, I've begun my search for the various chips used in Chapter 4. You can spend hours at Mouser.com or AllElectronics.com scanning through all their chips. One frustrating thing at AE was that in some instances, typing in the shortcut name such as 74HCXX wouldn't pull up anything... other times it did. I had better luck with Mouser but in some instances the picture was wrong - it would show a non-DIP switch for the thumbnail but the description/part# was what I wanted... OR... the picture was right but the description didn't match.
Rather than take a risk of ordering this stuff and not getting EXACTLY what I wanted, I chose to shop locally and pay a little more per chip. I was able to visually inspect every chip for the ID# and make sure it was of the DIP type. I also got all the chips inserted into two long plastic tubes that protect the chips legs/prongs from bending... not sure how Mouser.com and AE ship the chips, so please let us know if you order any and how they are shipped.
I got all my chips at ACK Supply here in Atlanta... definitely higher in price per chip but after looking at the shipping costs at Mouser and AE, it'll just about even out...
If you want to order from ACK, call 1-800-282-7954 and ask for Scott - just the 20 minutes he spent talking to me about the differences in chips, explaining the other letters not covered in the book (such as low voltage chips or military grade), and showing me some other chips I'll likely want to buy a few of later... totally worth the drive and extra cost. He was even able to help me find a replacement for the protoboard required in Exercise 15 that RadioShack no longer carries. I was able to fill my entire chip order with one visit and learn some more stuff to boot... nice guy.