Re: Temporal database

From: Frank Hamersley <terabitemightbe_at_bigpond.com>
Date: Wed, 24 Jan 2007 12:26:17 GMT
Message-ID: <JfIth.5761$u8.2741@news-server.bigpond.net.au>

Marshall wrote:
> On Jan 23, 4:32 am, Frank Hamersley <terabitemigh..._at_bigpond.com>
> wrote:

>> Marshall wrote:[..]
>>
>>> Another example of dividing the undividable:
>>> I can't think of anything more indivisible than the bit. Can't
>>> have less than a bit, can you? I mean, what could a third
>>> of a bit even mean? The very idea is ridiculous. And yet...
>>> I used to work on a system that had a character encoding
>>> that used 5 1/3 bits per character. That's right: five and
>>> one third bits for each character. 2^5.333 ~= 40.32;
>>> the character set consisted of 40 characters, each consuming
>>> about 5 1/3 bits. If you had 3 characters, that was 16 bits.
>>> 5 1/3 * 3 = 16.
>> OK - back it with enough detail to dispell all my concerns about the
>> veracity of your claim.  And please do not resort to averages.

>
> You have to actually express some concerns before I can dispel
> them. I can't just pluck them out of your mind after holding an
> envelope up to my forehead. Would it help you to figure out
> how it worked if I said that strings were always a multiple of
> 2 bytes in length?
>
> http://en.wikipedia.org/wiki/MODCOMP
>
> They used to have some of them at Lawrence Berkeley Labs
> where I worked in the early eighties.
>
> Oh, hell: just imagine three base-40 digits packed in to a
> 16 bit quantity. Fits nicely: 40*40*40 = 64000, not much left
> over at all. Each character consumes five and one third bits.

Interesting - this smells like the sort of system that a interplanetary spacecraft designer would feel compelled to build.

That said...did this gadget perform direct string/character operations on the triplets? I assume that single character strings cost 16 bits to store? Was it possible to directly address each of the 3 characters?

Personally I suspect that Darwin got the better of this gem as evidenced by the rather short wiki noting its demise (by adsorption).

Cheers, Frank. Received on Wed Jan 24 2007 - 06:26:17 CST

Re: Temporal database - no end date