6 ms·
32 bits that changed microprocessor design
- macshome 1y agoThe more that we find out about Bell Labs the more we all realize how much of our world they built. We really could use a place like that today.
- em3rgent0rdr 1y agoThere is a place like that today. It is called "Nokia Bell Labs".
- jll29 1y agoThis is a valid point. Are there still regularly ground-breaking innovations (which ones e.g. in the last decade) coming out of the same lab today, whatever its owner or name?
- rollcat 1y agoIt's more difficult to innovate today on a similar scale, or with similar impact. It also seems that big budgets don't really help. Graphene chips are an insanely exciting (hypothetical) technology. A friend of mine predicted in 2010 that these chips will dominate the market in 5 years' time. As of 2025 we can barely make the semiconductors. Apple makes chips that have both excellent performance per watt, and overall great performance, but they make small generational jumps. On the other hand, startups, or otherwise small-but-brilliant teams can still produce cool new stuff. The KDE team built KHTML, which was later forked into Webkit by three guys at Apple. Paxos was founded on theoretical work of three guys. Brin & Page made Google. In the era of big & expensive iron, the innovation was to use cheap, generic, but distributed compute power, and compensate for hardware failures in software. This resulted in cheaper, more reliable, and more performant solutions. But yeah, most of the "moonshot factories" just failed to deliver anything interesting. Maybe you need constraints, market pressure?
- dimator 1y ago> But yeah, most of the "moonshot factories" just failed to deliver anything interesting. Maybe you need constraints, market pressure? It's funny you say that because to me it seems like bell labs was the exact opposite. Because of the antitrust ruling, there was a cap on profits, so many monies were instead funneled into green field R&D. The facility was run by people who knew how to manage a large group of capable people: put them in close proximity with other cross discipline stars, get out of their way, let their imaginations dictate the path.
- rollcat 1y agoI can't quite put my finger on these changes in the landscape. Shuji Nakamura invented blue LEDs in his garage. Meanwhile, graphene. I just don't think there's a universal rule.
- justin66 1y agoThis comment was illuminating. It would indeed have been more accurate to say "we could really use people like that today." Where they're located is a secondary concern.
- deleted 1y ago[deleted]
- zik 1y agoThe Bellmac-32 was pretty amazing for its time - yet I note that the article fails to mention the immense debt that it owes to the VAX-11/780 architecture, which preceded it by three years. The VAX was a 32-bit CPU with a two stage pipeline which introduced modern demand paged virtual memory. It was also the dominant platform for C and Unix by the time the Bellmac-32 was released. The Bellmac-32 was a 32-bit CPU with a two stage pipeline and demand paged virtual memory very like the VAX's, which ran C and Unix. It's no mystery where it was getting a lot of its inspiration. I think the article makes it sound like these features were more original than they were. Where the Bellmac-32 was impressive is in their success in implementing the latest features in CMOS, when the VAX was languishing in the supermini world of discrete logic. Ultimately the Bellmax-32 was a step in the right direction, and the VAX line ended up adopting LSI too slowly and became obsolete.
- rst 1y agoYou might want to be more specific by what you mean by "modern", because there were certainly machines with demand-paged virtual memory before the VAX. It was introduced on the Manchester Atlas in 1962; manufacturers that shipped the feature included IBM (on the 360/67 and all but the earliest machines in the 370 line), Honeywell (6180), and, well... DEC (later PDP-10 models, preceding the VAX).
- mjevans 1y agoPeriod might be the best word. Contemporary is also a contender I thought of first, before disqualifying it for implying 'modern'.
- pinewurst 1y agoAlso Prime as well in the 70s pre-VAX.
- PaulHoule 1y agoMy impression of the VAX is, regardless of whether it was absolutely first at anything, it was early to have 32-bit addresses, 32-bit registers and virtual memory as we know it. You could say machines like 68k, the 80386, SPARC, ARM and such all derived from it. There were just a lot of them. My high school had a VAX-11/730 which was a small machine you don't hear much about today. It replaced the PDP-8 that my high school had when I was in elementary school and visiting to use that machine. Using the VAX was a lot like using a Unix machine although the OS was VMS. In southern NH in the late 1970s through mid 1980s I saw tons of DEC minicomputers, not least because Digital was based in Massachusetts next door and was selling lots to the education market. I probably saw 10 DECs for every IBM, Prime or other mini or micro.
- jandrese 1y agoThe article handwaves over why the chip wasn't a success, which makes my first thought of "how much did each chip cost" all the more relevant. This is such an uplifting story until you think about how the 8086 is just about to wipe it off of the map.
- dboreham 1y agoAT&T/Western Electric didn't really sell chips. They were a systems company. I actually used a machine with their VME boards (which iirc the company I worked for had been contracted to manufacture and market). Even to us the idea that Western Electric made CPUs seemed surprising. It was cool to be running System V on a desktop machine back then though.
- deleted 1y ago[deleted]
- adrian_b 1y agoDuring their early success years, Intel has made extremely few innovations. One of their few innovative products was the floating-point coprocessor 8087, which has changed completely how everybody does floating-point computations, and for which they were smart to hire external expertise (i.e. William Kahan) which has brought most of the innovative features. On the other hand, during those years Intel has been extremely good at adopting very quickly any important innovation made by a competitor, while also succeeding to obtain better manufacturing yields, so that they were able to have greater profits, even with cheaper products. Bellmac-32 has not been important commercially, but without it a product like Intel 80386 would have appeared only some years later. With 80386, Intel has switched their production of CPUs from NMOS to CMOS, like also Motorola had done one year earlier with 68020. Both Intel and Motorola have drawn heavily from the experience gained by the industry with Bellmac-32.
- marcosdumay 1y ago> while also succeeding to obtain better manufacturing yields AKA, Intel was extremely innovative in manufacturing. Turns out that because of Moore's law, that was the only dimension that mattered.
- joezydeco 1y agoIf you were a CS student at UIUC in the late 80s your sophomore weed-out class in C and assembly language coding was on this processor. It was a lot more fun to write for this core compared to Intel. And it was the only processor I ever used that had a STRCPY opcode.
- rasz 1y ago>STRCPY opcode. whats wrong with rep movsb?
- saagarjha 1y agoYou'd need to run strlen first.
- joezydeco 1y agoReal men just blast through memory until hitting a zero. If it's there at all.
- cesarb 1y ago> You'd need to run strlen first. I might be a bit rusty in my x86 assembly, but wouldn't "repnz movsb" be the x86 strcpy opcode, for zero-terminated strings?
- rasz 1y agoIf you care at least a little about buffer overflows You will run one anyway.
- willmarquis 1y agoBellmac-32 went 32-bit CMOS when everyone else was still twiddling 8-bit NMOS, then got shelved before the afterparty. IEEE giving it a milestone in 2025 is basically a lifetime achievement trophy for the domino-logic DNA inside every phone SoC today late, but deserved
- rkagerer 1y ago> With no CAD tools available for full-chip verification ... the team resorted to printing oversize Calcomp plots. The schematics showed how the transistors, circuit lines, and interconnects should be arranged inside the chip to provide the desired outputs. The team assembled them on the floor with adhesive tape to create a massive square map more than 6 meters on a side. Kang and his colleagues traced every circuit by hand with colored pencils, searching for breaks, overlaps, or mishandled interconnects.
- Findecanor 1y agoI read through its instruction set manual, and found an instruction with unusual behaviour: Its 'ASL` (arithmetic shift left) instruction. It shifts all bits except for the sign bit, leaving it unchanged. I have read many ISA's manuals and not seen this elsewhere. Most ISAs don't have separate arithmetic and logic left shift instructions. On M68K, which does, the difference between `ASL` and `LSL' is only that the former sets the Overflow flag if any of the bits shifted out is different from the resulting sign bit whereas the latter clears it.
- RetroTechie 1y agoZ80 has a Shift Right Arithmetic (SRA) instruction. From Zilog Z80 User Manual: "An arithmetic shift right 1 bit position is performed on the contents of operand m. The contents of bit 0 are copied to the Carry flag and the previous contents of bit 7 remain unchanged. Bit 0 is the least-significant bit." So if value was used as signed integer, that's a sign-preserving /2 (and easy to expand to 16 or more bits). Z80 also has a SLA, which does shift all bits.
- roelschroeven 1y agoFor right shifts, yes, instruction sets commonly have the distinction between arithmetic and logic. Findecanor was talking about left shifts though.
- Joker_vD 1y ago> So if value was used as signed integer, that's a sign-preserving /2 Only if you define your integer division as rounding towards minus infinity which almost none of the languages do (they usually round towards zero). See e.g. [0] for the additional instructions needed to correct the result. Now, I personally think this is a mistake and my PLs always round integers down instead of towards zero, but others may disagree. [0] https://godbolt.org/z/1z7eYPT48 https://godbolt.org/z/1z7eYPT48
- Findecanor 1y agoIt's a bit inconsistent that most ISAs out there have division that rounds towards zero but only right shift that rounds down. PowerPC is the only production-ISA I've found that has an arithmetic right-shift instruction designed for rounding towards zero. It sets the Carry flag if a 1 is shifted out and the result is negative. Then only an "add with carry" instruction is needed to adjust the result.
- didgetmaster 1y agoMy very first computer was an AT&T 6300 that I bought in 1986. It came with an Intel 8086 processor.
- zahlman 1y ago> Why Bellmac-32 didn’t go mainstream This is the main thing I wanted to know, the last section heading in the article, and not explained by the remaining text. AT&T choosing someone different is a lame excuse (others could have bought in, like how Apple got ideas from Xerox PARC), and the rest is padded out with a restatement of how the Bellmac-32's ideas shaped future chip development.
- kazinator 1y agoThe Wikipedia page says "[the Bellmac 32] was designed with the C programming language in mind". This is the real first, more significant than anything else. Hardware design catering to the C language started here.
- zombot 1y ago> “Ma Bell” had dominated American voice communications, with its Western Electric subsidiary manufacturing nearly every telephone found in U.S. homes and offices. When others do it, they call it communism. When they do it themselves, they call it good business.