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"The MR BIOS on my board is quite confused and reports the CPU to be 586SX, which I like" I think that's correct though. From what I can find, Intel renamed 5
by tyingq 5y ago
"The MR BIOS on my board is quite confused and reports the CPU to be 586SX, which I like"
I think that's correct though. From what I can find, Intel renamed 586 to 586SX after they released their MMX capable Pentiums. So "non-MMX Pentium" is supposed to be 586SX. "MMX Capable Pentium" is 586DX.
- monocasa 5y agoYeah, it's why it's Pentium has the 'pent' in it, being the '5'86.. IIRC the trademark office told them they couldn't just trademark a number so they did the next best thing.
- _0ffh 5y agoYep, at the time we were jokingly speculating if the next generation would be called Hexium. =)
- formerly_proven 5y agoI'm still disappointed that AM4 isn't PGA1337 and that they never released an AMD Furion.
- anyfoo 5y agoI was relatively young at that time, and actually a bit disappointed that it was called "Pentium Pro" instead.
- lostgame 5y agoThat’s fascinating to know! I’d personally had a 386 and 486 before I finally got a Pentium, and I never understood the significance of the nomenclature. That’s super neat!
- anyfoo 5y agoThey were also often prefixed with "80" until the 486, before the first of them, because they all came from the 8086, which was the first of the successor line of the 8080 CPU (or rather its 8 bit bus sibling 8088 was). After that came the 80186, which was not used in IBM compatible PCs (but in non-compatible ones) because it was more of a microcontroller and came with integrated but incompatible peripherals (like an interrupt controller). The CPU itself was still compatible, though. So were 80286, 80386, 80486 and everything after that. They all added stuff obviously, often massively, but they still all can run 8086 software. Though I've lost track of what's happening with Intel CPU as of recently, I just have some dim and unreliable recollection that real mode might finally have been removed altogether, not sure.
- anyfoo 5y ago> until the 486, before the first of them Should read "until the 486, before the Pentium".
- FartyMcFarter 5y agoWasn't the Pentium Pro also known as i686? I don't think there was ever an Intel 786 though.
- monocasa 5y agoIt was. You can see that in gcc target triples.
- userbinator 5y agoIf you go by the CPUID family identifier, then essentially everything from the Pentium Pro to the latest x-Lake are all in the P6/686 family. The only exceptions are Netburst (P4) with a family of 15(!), the GPU-ish Knight's Ferry/Corner in family 11, and Quark with its Pentium-level instruction set still in family 5. https://en.wikichip.org/wiki/intel/cpuid https://en.wikichip.org/wiki/intel/cpuid
- the_snooze 5y agoI prefer the joke explanation. Each new processor line got its name by doing the calculation of incrementing the previous one by 100: 286 --> 386 --> 486 --> 585
- InvaderFizz 5y agoFor those that weren't around for the release of the original Pentium CPUs, this off-by-one error is a callback to the bug[0] in the FPU. Hilarious. 0: https://en.m.wikipedia.org/wiki/Pentium_FDIV_bug https://en.m.wikipedia.org/wiki/Pentium_FDIV_bug
- deleted 5y ago[deleted]
- gerdesj 5y agoI'm old enough (50) and (80)486 was the last numbered chip from Intel, in my experience. 586 never happened. The SX DX thing happened at the 386 and 486 level. All a bit confused and boiled down to whether you got a maths co-processor or not. Looking back it was a pretty rubbish thing. We consumers have been treated like complete twats by all CPU manufacturers for decades.
- 300bps 5y agoConfusing, but 386SX vs 386DX had nothing to do with math coprocessors. That was only on the 486DX which had a math coprocessor vs 486SX which did not. https://dfarq.homeip.net/386sx-vs-386dx-a-misunderstood-difference/ https://dfarq.homeip.net/386sx-vs-386dx-a-misunderstood-diff...
- mobilio 5y agoJust like difference between 8086 and 8088
- tyingq 5y agoYes, they didn't market it that way, but CPUID returned '5', where a 486 returned '4', a 386 '3', etc. You'll find the 586 references in lots of Intel documentation.
- anyfoo 5y agoIt's also in the DX register (DH specifically) after reset. Earlier CPUs did not have CPUID, so that's what the BIOS most likely used. "DX holds a component identifier and revision number after RESET as Figure 10-1 illustrates. DH contains 3, which indicates an 80386 component."
- jacquesm 5y agoPenta = five, the chip was slated to become the 586 but then marketing got involved and wanted something more sexy than just another number.
- anyfoo 5y agoTotal speculation, but the "5" could well be because the BIOS displays whatever the CPU had in its DH (the upper half of DX) register after reset. I remember a few tools that were made before the Pentium was a thing, that also reported "586" when you tried them out on one. (If I remember correctly, the BIOS also has/had a BIOS function to relay that value to a program.) From the 80386 programmer's reference manual: "DX holds a component identifier and revision number after RESET as Figure 10-1 illustrates. DH contains 3, which indicates an 80386 component."