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Very senior embedded real-time systems programmer (Texas law is very picky about the use of the term "engineer"), unsuccessful candidate for U.S. Congress, and unreconstructed Cold Warrior.

Jan
18
reviewed Close ruby for desktop app or web app development
Jan
18
reviewed Leave Open Do any object-oriented programming languages support “collective constructors”?
Jan
18
reviewed Leave Open Dynamically vs Statically typed languages studies
Jan
18
awarded  Custodian
Jan
18
reviewed Close what is the difference between a software engineer and project manager?
Jan
18
comment Where are octals useful?
Your comment about PDP-11 documentation is incorrect. The PDP-11 had 8 registers. R0-R5 were general purpose registers. R6 was the stack pointer, and R7 was the PC. The MOV instruction took two 3-bit register numbers and two 3-bit addressing modes. Octal captures the register and mode fields PERFECTLY. (I strongly doubt that this was an accident.) Using hex would have confused everything. PUSH and POP were just addressing modes that used R6. Immediate operand was an addressing mode that used R7.
Jan
17
comment Why do we still use floats?
3.14159265358979..., if I remember correctly. See piday.org/million
Jan
17
comment Will we go back(?) to fixed-point arithmetic in the near future?
@JanHudec: Again, yes and no. A particular fixed-point type will always have the binary point assumed at a certain position. However, two DIFFERENT fixed-point types may not have the binary point in the same place. It is not usually necessary to add or subtract different fixed-point types. However, they get multiplied, and the results summed (sum-of-products, also known as FIR filter) ALL THE TIME. Depending on what you are doing, you may have to rescale the sum. (Think about normalized least mean squares filter processing.) (Note: I do this for a living.)
Jan
17
awarded  Enlightened
Jan
17
awarded  Nice Answer
Jan
17
comment Will we go back(?) to fixed-point arithmetic in the near future?
@JanHudec: Yes and no. In order to do a fixed-point addition or subtraction, the two numbers must have the binary point IN THE SAME PLACE, or one of them must be shifted to line up the binary points. (Think about adding 12.34 to 0.000125.) On a multiplication or division, you have to consider the two arguments, each with a known binary point position, and figure out where the result binary point shows up. (Consider multiplying or dividing 12.34 by 0.00125.) Avoiding those headaches are why floating-point was invented. Read Hamming's book.
Jan
17
revised Will we go back(?) to fixed-point arithmetic in the near future?
Clarify cost of hardware integer divide vs. hardware floating divide. Add historical note.
Jan
17
comment Why do we still use floats?
The dedicated devices frequently have to do a LOT more processing, in a limited amount of time, than the "general computing platforms". The dedicated devices generally have far lower power and cooling budgets. Last time I looked, you couldn't put an Intel flagship processor in a pocket cellphone, because of the power and cooling requirements.
Jan
17
comment Will we go back(?) to fixed-point arithmetic in the near future?
@delnan: The key concept is that floating-point operations (all of them, not just division) are easier FOR THE PROGRAMMER, and not much harder for the machine. Fixed-point integer computation requires the programmer to do a huge amount of MANUAL bookkeeping to keep track of the decimal (binary) point. This is the kind of thing that computers (at first, software libraries) and hardware (later) are very good at. Read Hamming's book.
Jan
17
comment Will we go back(?) to fixed-point arithmetic in the near future?
@delnan: Yes, of course. However, the results then have to be renormalized, and final exponents calculated.
Jan
17
comment Why do we still use floats?
Actually, a lot of audio signal processing is done with integer DSPs. For speech, 16-bit sampling and integer processing is quite sufficient. For music, 24 bits is probably preferable: the Access Virus synthesizers use Freescale 24-bit integer DSPs. 32-bit float DSP doesn't buy you anything over 24-bit integer DSP.
Jan
17
answered Will we go back(?) to fixed-point arithmetic in the near future?
Jan
14
awarded  Nice Answer
Jan
14
answered Why do so many languages treat numbers starting with 0 as octal?
Jan
13
revised What should be the maximum length of a function?
Correct capitalization of FORTH.