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Questions tagged [floating-point]

for questions about floating point arithmetic. May be about the format of the word, or an instruction set, or a particular implementation.

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Which pre-IEEE computers had a single precision FPU and implemented double precision floats in software?

Before the formats of floating point numbers have been standardized in IEEE 754 in 1985, different vendors had used many different floating point formats, some of them listed on the Data Format and ...
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2answers
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Floating Point on Konrad Zuse's computers

From what I understand, with floating point arithmetic, shifting values up and down is important, since a floating point value essentially is an equation like 2e×m. This supposition may be supported ...
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2answers
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Using C64 floating point kernal routines with 16 bit integer

How to use floating point kernal routines for 16 bit arithmetics such as: $1234*$ABCD or $1234/$ABCD ?
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11answers
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Why not use fractions instead of floating point?

Considering all those early home computers, the ZX Spectrum, the Galaksija, the VIC-20, the Apple I/II/III, and all of those, they all have some 8-bit CPU which does integer arithmetic and no floating ...
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1answer
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“Quintword” is this a real word?

From the book Modern X86 Assembly Language Programming Quintword 80 Double extended-precision floating-point, packed BCD It goes on to say, Not surprisingly, most of the fundamental data ...
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1answer
214 views

How adequate would 48-bit floating point be? [closed]

Though power of 2 word sizes look in hindsight like a natural consensus, historical computers used quite a wide variety, including but not limited to 9, 18, 36, 12, 24 and 60 bits. Power-of-2 ...
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3answers
2k views

Floating point performance of classic minicomputers

Are there any numbers available for the floating point performance of classic minicomputers of the seventies and eighties? For example, the VAX 11/780 for integer calculations was generally rated in ...
9
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1answer
462 views

128-bit floating point

IEEE 754 defines 128-bit floating point, though perhaps in a three-way chicken and egg problem, it's rarely supported by hardware, rarely supported by compilers, and rarely used. Have there been, ...
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3answers
809 views

What other computers used this floating-point format?

I have discovered that the DEC PDP-10 used a floating-point format that differed from IEEE-754 in an interesting way. IEEE-754 is like sign-magnitude representation. The only difference between a ...
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1answer
309 views

When were floating point rounding modes first implemented?

It appears that at least some pre-IEEE 754 computers had only one hardwired floating point rounding mode, e.g. away from zero as in PDP-11 (page 154 of PDF). Which historical architectures were the ...