Tuesday, September 03, 2024

Spelunking CACM, vol. 21 (1978): Cray-1, RSA, CSP, and more, more, more!


WOW, the January issue is a must-read!

 It's chock full of papers on some of the most important architectures, both contemporary and historical, in a special issue, though at a glance I don't see an introduction. (But I don't see the front matter in the Digital Library...hmmm?)

  • The Manchester Mark I and Atlas. 'Nuff said. Know your history, kids. Interesting that these two bracket the transistor computer, first developed at Manchester.
  • MU5: This one, I wasn't familiar with, but it's from Manchester, one of the most important places in computer architecture history. Manchester's accomplishments include building the world's first transistor computer. (Wait, didn't I just say that?)
  • Sperry-UNIVAC 1100: a still-active family of 36-bit mainframes (36 bits???), the first of which were vacuum tubes, later transistorized ones with SSI and MSI (I presume). Although the names in the series followed the 11xx convention, the later ones weren't compatible with the earlier ones. Interestingly, this architecture used ones-complement integer arithmetic instead of twos-complement, so it's theoretically possible to have both +0 and -0 values. Like the DECsystem-10 below, it supported unlimited indirect addressing.
  • DECsystem 10: TOPS-20 systems, the next generation of this system, were workhorses at USC/ISI when I first worked in the computer center there. This architecture has a couple of clever, elegant features: essentially a single addressing mode, where the registers are the lowest handful of addresses, and indirection, where any pointer you follow has a bit that says, "Treat this one as pointer instead of the data you're looking for, and follow it." Yes, that could recurse. The OS was innovative, too. Oh, and did I mention that this marvelous has a word length of...36 bits?!? (Didn't I just say that?)  And that a byte can one of several sizes, with 7 and 9 bits being the most common?
  • The Cray-1: the most important supercomputer in history, perhaps, and a beautiful, elegant piece of work. Check out that gorgeous image at the top of this posting. Freon liquid cooling, chained 64-bit floating point vector operations working from vector registers, bipolar memory chips, dual-rail encoding to reduce fluctuation in power and signal noise, and the totally 1970s naugahyde love seat around its set-of-wedges circular design. 138 sustained megaFLOPS, what performance! Fastest machine in the world.

I'm tempted to just stop here and declare victory after January, but I suppose I should at least glance through the other issues...let's see, another report on status of women and minorities in CS faculty...

Ahem. Ah. Let's see, this might be important:

The RSA (Rivest-Shamir-Adelman) public key cryptosystem. Yeah, I'd say that's worth mentioning. Oh, and then Merkle, too. And at the end of the year Needham-Shroeder. A good year for cryptography.

Backus's Turing Award lecture. Want to think about programming languages? Read this first.

It was also an incredible year for the theory of distributed systems. Lamport on Time, clocks, and the ordering of events in distributed systems. One of the classic, classic papers in distributed systems. I still have my students read this, almost half a century later. Tony Hoare's Communicating Sequential Processes. Another of the classic, classic papers. And Per Brinch Hansen's own model for distributed programming. His affiliation is listed as USC, but I never met him; I have no idea when he left USC.

My sister's dog likes to lie on her back and just wallow.  I'm tempted to do that while reading all of these fantastic papers!

No comments: