freek@fwi.uva.nl (Freek Wiedijk) (11/06/90)
What is a "Count Zero Interrupt"? Gibson says: "On receiving an interrupt, decrement the counter to zero". What does this mean? On which machine(s) is this interrupt present? Freek "the Pistol Major" Wiedijk E-mail: freek@fwi.uva.nl #P:+/ = #+/P?*+/ = i<<*+/P?*+/ = +/i<<**P?*+/ = +/(i<<*P?)*+/ = +/+/(i<<*P?)**
mg20+@andrew.cmu.edu (Michael Paul Greelish) (11/07/90)
Well, I ain't no machine-language hacker, in point of fact I haven't programmed in *ANY* language in about two years, but: Count Zero Interrupt: I believe this command exists in at least the 6502 microprocessor's vocabulary (I grew up with a 6502 machine, but I programmed it in BASIC (please, no cheap shots)). To understand what this is, you must know what is a(n): interrupt: a break in normal program flow, either deliberate or accidental (I think) counter: also known as a register. It's simply a single-byte memory space containing a number 0-255. (On a 6502, at least.) decrement: actually, "reset" would be a better word here So, a count zero interrupt could be defined as: If there is an interrupt, reset the counter (register) to zero. ______________________________________________________________ |\ /| | \/ | ike Greelish Carnegie-Mellon U. undergrad quote: "CMU is as close to artificial reality as you can get in 1990." stupid disclaimer: My opinions are dictated to me by a 23 year old telepathic Chilean aardvark living in my closet.
firth@sei.cmu.edu (Robert Firth) (11/08/90)
In article <4bC2VW600VIE094FUA@andrew.cmu.edu> mg20+@andrew.cmu.edu (Michael Paul Greelish) writes: >Count Zero Interrupt: >If there is an interrupt, reset the counter (register) to zero. This feature also exists in several varieties of peripheral device controller, for instance the PDP-11 programmable clock (KW-11P of happy memory) has a 16-bit decrementing counter. However, the meaning is the reverse of Michael's statement: when the counter reaches zero, generate an interrupt. In this case, the interrupt signals the end of a programmed interval of time; in other cases, for instance an interrupt from a data transfer device, it might signal completion of a multi-byte (or whatever) transfer.
ap1i+@andrew.cmu.edu (Andrew C. Plotkin) (11/08/90)
> Excerpts from netnews.rec.arts.sf-lovers: 7-Nov-90 Re: Count Zero > Interrupt Michael P. Greelish@andr (1067) > Count Zero Interrupt: > I believe this command exists in at least the 6502 microprocessor's > vocabulary (I grew up with a 6502 machine, but I programmed it in BASIC > (please, no cheap shots)). Nope. I dearly love my old Apple 2; but I have to admit that the 6502 handles interrupts the way a drunk gorilla handles fine china. --Z
gourdol@imag.imag.fr (Gourdol Arnaud) (11/08/90)
I don't think Gibson is a computer expert, and I think what he meant was BEQ : Branch On Equal, that is interrupt program flow when a counter(register) is zero. However, this s only a supposition... Arnaud.-- /======================//==========================================/ / Arnaud Gourdol. // On the netland : gourdol@imag.fr / /======================//==========================================/
jp@dce.ie (John Pelan) (11/10/90)
The exact quote is;
COUNT ZERO INTERRUPT
-On receiving an interrupt, decrement the counter to zero.
Note that this is neither when a counter underflows generate an interrupt
or when an interrupt is generated 'reset' the counter to zero.
The term looks decidedly made-up and has no resemblance to any m/c instruction
or counter chip function that I've ever encountered. For it to be m/c the
CPU must have some sort of counter (*not* the same as a register!). It'd
definitely have it's uses (for pulse generation say) but not enough that
it'd warrant an instruction all of its own. You could quite easy implement it
with a couple of instructions on any CPU. Looks like Gibson was misinformed
or he misquoted.
--
John Pelan (jp@dce.ie)
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Splice the main() brace { | Traditional nautical programmers saying.
--------------------------------------------------------------------jimf@idayton.field.intel.com (Jim Fister) (11/10/90)
>Looks like Gibson was misinformed >or he misquoted. I've listened fairly passively to all this, but I'd like to add my two cents if I may. I always thought that this statement was one of those poetic liscense (sp) kinda' things. The idea was that if our hero got noticed by the big boys, or big silicon piles, or whatever, our hero was then toast. I honestly forget, but wasn't that statement near the climax of the book when every protaganist in the story was inches away from being smeared across pavement/space/building fronts? Just some input from a former English Major and full-time Cyberpunk junkie. Greetings from the Rocking Metropolis. JimF
miodeen@buddha.ncc.umn.edu (Mike Odeen) (11/12/90)
Currently an English major and Gibson reader, myself, I'd like to respond to Jim Fister's comment on Count Zero. COUNT ZERO INTERRUPT--On receiving an interrupt, decrement the count to zero. References to computer jargon aside, a literal reading of the line might be: When you are interrupted, start over. This is a very stong thematic element throughout the novel. The three stories woven through the novel recount how each character's life is somehow dramatically interrupted, and subsequently how the characters must begin their lives anew. Everyone of the characters is given an interrupt, forced to go back to "zero". They must reevaluate their own identities, how they view the world, what they expect out of life and where they are going. These kinds of crisisses face all of the major characters: Turner--a number of times, Bobby, Marley, and to some extent Angela Mitchell. I enjoy this kind of discussion of Gibson's work, a body which lends itself well to thoughtful criticism, and look forward to future discussions of his work in thisd forum. -- Michael J. Odeen miodeen@buddha.ncc.umn.edu
anderson@well.sf.ca.us (11/14/90)
>The exact quote is; >COUNT ZERO INTERRUPT >-On receiving an interrupt, decrement the counter to zero. >The term looks decidedly made-up and has no resemblance to any m/c instruction >or counter chip function that I've ever encountered. For it to be m/c the ... >with a couple of instructions on any CPU. Looks like Gibson was misinformed >or he misquoted. >John Pelan (jp@dce.ie) In interview Gibson said excess knowledge of computers would interfere with his ability to create the imagery for which he is known... ******************************************************************************** David E. Anderson, Redwood City, CA (415) 592-1101 Independent Database Consultant (formerly with Oracle kernel Support Group) anderson@well.sf.ca.us ******************************************************************************** First learn your horn and all the theory. Next develop a style. Then forget all that and just play. Charlie Parker [?]
pete@minster.york.ac.uk (11/15/90)
In article <21651@well.sf.ca.us> anderson@well.sf.ca.us writes: > >In interview Gibson said excess knowledge of computers would interfere >with his ability to create the imagery for which he is known... > Yes -- he's been caught saying things like that before. Remember the bit in ``Neuromancer'' where, after all the hi-tech shenanigans in Cyberspace, the fancy console decks etc., Case asks someone if they have a modem! Gibson admitted that the only reason he used such an archaic word (compared to the technology in the novel!) was because he liked the sound of it... Pete Fenelon (pete@minster.york.ac.uk)