SPI and I2C, was Re: Raspberry Pi and America,

On 2 Jul 2012 at 20:25, Dave McGuire wrote: No, but I suspect a resurgence might occur in some of the old ideas. One such is that as word length increases beyond a certain limit (say, 64 bits), lareg *integers* are less important, particularly if they exceed the width of an address. In that case, it makes sense to treat integers as a special case of floating point. Thus, in a 64-bit machine, an integer may have a range of only +/-2^47-1 (48 bits); a short, only 24 bits; a long 96 bits. It was thus on machines as late as the ETA-10 (I don't recall if Cray ever adopted that convention) and I wouldn't be surprised to find a modern system that operated that way. And one of these days, I expect to see a variable-word length CPU again. Variable-length BCD arithmetic might be considered a boon by the financial people. --Chuck