Talk:Intel 80386
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I've seen sources that say the chip was released in 1985. [[1]]. Was it really 1986 or was it 1985? Timbatron 21:42, 25 December 2005 (UTC)
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- The chip taped-out in October 1985 (I was there). It was not "released" until (IIRC) late 1986, as at the time there was a long lead-time between tape-out and public availability. -- Gnetwerker 08:08, 3 February 2006 (UTC)
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[edit] Sources
"Intel decided against producing the chip before then, as the cost of production would have been uneconomic." What is the basis for this assertion? The chip wasn't designed until Oct '85, this implies otherwise. -- Gnetwerker 08:08, 3 February 2006 (UTC)
[edit] Customers
I think it is significant that the first major customer was Compaq, then not a large company, rather than IBM. While I "know" this (from being at Intel), I don't have a source. Anyone? (P.s. -- The Compaq page says all of these things without attribution.) -- Gnetwerker 08:11, 3 February 2006 (UTC)
[edit] SX-DX
Does anyone know what SX and DX stand for? I heard once "Single eXecution" and "Double eXecution". But I've never seen that confirmed. warpozio 14:04, 27 March 2006 (UTC)
SX and DX means very different things, depending on processor's generation. 80386SX internally is identically the same as DX (fully 32-bit), but it has 16-bit data bus, which slowed down it's memory access performance comparing to 80386DX, which had 32-bit data bus. In this matter it's similar to Motorola 68000, which is also a 32-bit processor internally (32 bit addressation, registers, arithmetic), but also has 16-bit data bus. It was done to minimize the costs of motherboards - 68000 was out much earlier than 80386SX. Also, first 80386 of course has 32-bit data bus, thus is was the "DX", yet it wasn't called so, because 80386SX and separation between SX and DX was introduced later.
In the 486 generation processors SX versions doesn't have built-in FPU. Of course 80386 never has integrated FPU, thus 486SX at the same frequency is something like faster 80386DX (faster due architectural advances - pipelined ALU and so on). Yet, AMD has managed to produce 80386DX working at quite high frequencies (40Mhz), thus is often was faster than 486SX with lower freqs like 25Mhz.
SX and DX are mostly marketing features, which are introduced to separate lower and upper segments of market. In such meaning they are something like "Celeron" and "Pentium" trademarks used todays. Though different generations of processors use different ways to "cripple" the performance in low-cost models.
- You didn't read the question, Mr Unsigned. You answered a question that was in your head. The gentleman wanted to know what the letters DX and SX stood for. You let him down, and that upsets me. Lupine Proletariat 14:55, 18 May 2006 (UTC)
[edit] 80287
Assembler manuals claims that original 80386 could work with 80287 processor - to save one's investments, or to allow intemediate price-and-perfomance level between FP-less sole 80386 and expensive 80386+80387 pair
[edit] Multiply bug
OK, why delete that section? It's significant - the first Intel '32 bit' CPU didn't, you know, actually work and Intel ended up stamping thousands of chips '16 bit only'. Several important programs (eg Windows) checked for this. Lovingboth 22:30, 29 October 2006 (UTC)
