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No new general-purpose registers were added. 16-bit registers all became 32-bit, the extension usually being marked by the addition of an "E" to their mnemonics. Thus, AX became EAX and BP became EBP. The segments which contain executable code can be marked as containing either 16 or 32 bit instructions, in order order to preserve compatibility with the earlier models. In addition, a special prefix can be used to include 32-bit instructions in a 16-bit segment and vice versa. |
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No new general-purpose registers were added. All 16-bit registers except the segment ones were expanded to 32 bits. Intel represented this by adding "E" to the register mnemonics (thus the expanded AX became EAX, SI became ESI and so on). Since there was a greater number of registers, instructions and operands, the machine code format was expanded as well. In order to provide backwards compatibility, the segments which contain executable code can be marked as containing either 16 or 32 bit instructions. In addition, a special byte prefix can be used to include 32-bit instructions in a 16-bit segment and vice versa. |
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1996 saw the appearance of the MMX? (Multimedia Extensions) technology by Intel. While the new technology has been advertised widely and vaguely, its essence is very simple: MMX added 8 64-bit registers to the Intel Pentium CPU design. Instructions were added to the CPU so that it could support moving the registers' contents from and to the memory, and perform arithmetic operations upon them quicker and with more convenience than before. |
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1996 saw the appearance of the MMX? (Multimedia Extensions) technology by Intel. While the new technology has been advertised widely and vaguely, its essence is very simple: MMX added 8 64-bit registers to the Intel Pentium CPU design. Instructions were added to the CPU so that it could support moving the registers' contents from and to the memory, and perform arithmetic operations upon them more quickly and with more convenience than before. |
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