thumb


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Related to thumb: Trigger thumb

thumb

1. the first and usually shortest and thickest of the digits of the hand, composed of two short bones
2. the corresponding digit in other vertebrates
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

Thumb

(processor)
An extension to the Advanced RISC Machine architecture, announced on 06 March 1995 by Advanced RISC Machines Ltd. By identifying the critical subset of the ARM instruction set and encoding it into 16 bits, ARM has succeeded in reducing typical program size by 30-40% from ARM's already excellent code density. Since this Thumb instruction set uses less memory for program storage, cost is further reduced.

All Thumb-aware processor cores combine the capability to execute both the 32-bit ARM and the 16-bit Thumb instruction sets. Careful design of the Thumb instructions allow them to be decompressed into full ARM instructions transparently during normal instruction decoding without any performance penalty. This differs from other 32-bit processors, like the Intel 486SX, with a 16-bit data bus, which require two 16-bit memory accesses to execute every 32-bit instruction and so halve performance.

The patented Thumb decompressor has been carefully designed with only a small amount of circuitry additional to the existing instruction decoder, so chip size and thus cost do not significantly increase. Designers can easily interleave fast ARM instructions (for performance critical parts of a program) with compact Thumb code to save memory.

thumb

(jargon)
The slider or "bubble" on a window system scrollbar. So called because moving it allows you to browse through the contents of a text window in a way analogous to thumbing through a book.
This article is provided by FOLDOC - Free Online Dictionary of Computing (foldoc.org)

thumb

(1) See scroll bar and thumb culture.

(2) (Thumb) An extension to the architecture of an ARM chip that provides enhanced code density. It stores a subset of 32-bit instructions as compressed 16-bit instructions and decompresses them back to 32 bits upon execution. See ARM.
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References in classic literature ?
TOM THUMB went up the kitchen chimney and looked out at the top--there was no soot.
WHILE Tom Thumb was up the chimney, Hunca Munca had another disappointment.
THEN those mice set to work to do all the mischief they could--especially Tom Thumb! He took Jane's clothes out of the chest of drawers in her bedroom, and he threw them out of the top- floor window.
WITH Tom Thumb's assistance she carried the bolster down-stairs and across the hearth-rug.
But they were not so very, very naughty after all, because Tom Thumb paid for everything he broke.
My clothes were all sodden with dew, and my coat-sleeve was drenched with blood from my wounded thumb. The smarting of it recalled in an instant all the particulars of my night's adventure, and I sprang to my feet with the feeling that I might hardly yet be safe from my pursuers.
The firemen had been much perturbed at the strange arrangements which they had found within, and still more so by discovering a newly severed human thumb upon a window-sill of the second floor.
I have lost my thumb and I have lost a fifty-guinea fee, and what have I gained?"
Then she lifted both hands, with all the fingers and thumbs spread out, and cried:
He held up his two hands as he spoke, and showed that the thumbs and two first fingers had been torn away from each of them.
On a positive note, conservative treatments, lifestyle modifications, and simple adaptive techniques can help the majority of people with arthritis or other thumb problems improve their function and regain their quality of life.
Parents allege that their baby was admitted to Vadilal Sarabhai Hospital in the city on Thursday and her thumb was cut off along with the bandage.