Path: ...!news.misty.com!news.iecc.com!.POSTED.news.iecc.com!not-for-mail From: John Levine Newsgroups: comp.arch Subject: Re: The Design of Design Date: Sun, 21 Apr 2024 21:45:57 -0000 (UTC) Organization: Taughannock Networks Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Date: Sun, 21 Apr 2024 21:45:57 -0000 (UTC) Injection-Info: gal.iecc.com; posting-host="news.iecc.com:2001:470:1f07:1126:0:676f:7373:6970"; logging-data="63850"; mail-complaints-to="abuse@iecc.com" In-Reply-To: Cleverness: some X-Newsreader: trn 4.0-test77 (Sep 1, 2010) Originator: johnl@iecc.com (John Levine) Bytes: 3055 Lines: 41 It appears that Thomas Koenig said: >An interesting detail about the /360 design was that they originally >wanted to do a stack-based machine. It would have been OK for the >mid- and high-end machines, but on low-end machines it would have >been undompetetive, so they rejected that approach. The 1964 IBM Systems Journal paper has half a page on that. They felt it would be about as good for scientific machines, worse for commercial. Stack machines have more compact instructions due to zero-address, but they need more instructions to move stuff around in the stack so that was a wash, and the performance depends on how much of the stack it can keep in fast memory. The 360 had way more registers than any previous IBM machine. The 7094 had accumulator, MQ, and 7 half length index registers. STRETCH had an overcomplex architecture with 7 fast registers, mostly special purpose. Some of the commercial machines had an odd circular store treated as some number of variable length registers. They had the insight to see that the 16 fixed sizs registers could be in fast storage on high end machines, main memory on low end machines, so the high end machines were fast and the low end no slower than a memory-memory architecture which is what it in practice was. It was really an amazing design, no wonder it's the only architecture of its era that still has hardware implementations. >He discusses the book on computer architecture he co-authored with >Gerrit Blaauw in it (as a project). Would be _very_ nice to read, >but the price on Amazon is somewhat steep, a bit more than 150 Euros. I have a copy. The first half is the textbook, which is pretty good. The second half is descriptions and evaluations of 30 architectures from Babbage and the Mark I to the 6502 and 68000, which are great. I see a used copy here for $105 which is what textbooks cost these days: https://www.valore.com/textbooks/computer-architecture-concepts-and-evolution-1stth-edition/0201105578 -- Regards, John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies", Please consider the environment before reading this e-mail. https://jl.ly