Re: Anyone want custom hp41 rompacks? Message #11 Posted by Howard Owen on 21 Sept 2005, 10:13 p.m., in response to message #10 by don wallace
Hmm. Lots of grist for the mill in this one! 8)
Quote:
The thing is, my clonix clone does not latch up or crash.
That's gotta be a positive factor.
All other things being equal, I'd say that one could be definitive. 8)
Quote:
...
With regard to the service module just being software,
how then would it be able to calculate processor clock speed?
(Think carefully before you answer...)
Good question. Seems like you'd need an external reference.
Quote:
I'm not hp, but if I had designed the service rom (maybe I am getting confused with the diagnostics rom?)
Maybe. Or maybe I'm the one who is confused. I wasn't aware there was a diagnostics ROM as distinct from the service ROM.
Quote:
Contrary to what programmers think (and I am not having a go at anyone here, just being honest and speaking from some experience),
Oh, yeah. And it's "to-may-toe" I tell ya! 8)
Quote:
there is a lot of stuff you can do very differently with hardware or which requires hardware to implement. Turing might not agree, but then he was a mathematician and not an engineer.
It's two levels in the abstraction layers we wrap around the mapping of the motion of electrons and photons into informationi processing. There is therefore no necessary disagreement. Alan Turing invented the field of Computer Science in one fell swoop in 1936. His work was pure Mathematics. And while it was revolutionary in scope and impact, it bore no relation to any physical machine doing real computational work. (This was before Bletchley Park, remember.)
Real computers have to deal with real electrons traveling through real circuits. Considerations of timing, temperature, conductivity, permissivity, crankiness, colic and gout are paramount. 8) There is plenty of theoretical work underpinning Electrical Engineering too, but the impact of the real physical world makes EE a whole different art form than CS. I say this as one who is untrained in the former and self-taught in the latter. (I have had frequently to make software work for EEs, MEs and Physicists in the past, so I am familiar to some degree with how they think. I've also formed some conclusions about why they think the way they do, which I'm saving for my Magnum Opus: "Everything I Need to Know I Learned by Cleaning Up After Computer Users Too Clever By Half To Clean Up After Themselves". The title is tentative. I may need to flesh it out a little more.)
So it's all well and good to conceive of an abstract machine, and to investigate its properties, thereby founding a new branch of Mathematics. (It's actually damned good, far exceeding anything most of us, or me at least, could even aspire to acheiving.) But it's another trick entirely to go and implement a physical system that embodies the abstract machine. And to expect that physical system (or multi-layerd systems of systems) to behave purely according to the abstract machine model is silly.
Quote:
Babbage was way ahead of his time sadly for him, but his hardware solution to computation is interesting in that it actually works... I'd hate to have to actually compute on the original Turing machine. Do you see my point?
I think so. 8)
I've heard it said, by the way, that Babbage was too much the Mathematician to design systems that could realistically be implemented with the available technology. I'm aware that a group in England created an Analytical Engine using machining techniques of the time. But "realistically" includes not only the mechanical engineering, but the financial wherewithall. That's another whole level of abstraction, God help us.
Somewherre I saw a modified ISO model of networks that illustrates this:
Religious <-- You are here
Financial
Application
Presentation
Session
Transport
Network
Data Link
Physical
Quote:
On a different related subject this quiz might be interesting:
Q. The most complex software in the world is found:
a: In UNIX (/LINUX)
b: In Micro$oft Windows XP / NT4 etc...
c: In the space Shuttle take-off / landing Computer
d: In AT&T's 4ESS telephone switching system (or whatever it's called nowadays)
You might just be surprised at the answer...
I think it's the phone switching system. It's an enormous, distributed computer. Linux is less complex than the NT code base, to judge by number of lines and tendency to crash. So I'd place Windows and Linux at 2 and 3. The software for landing the space shuttle has to run on some pretty old machines, so I'll put that as the least complex.
I answered that off the top of my head, and will not change it if I got it wrong.
Quote:
Q. In the correct answer above the largest proportion of the code is devoted to:
a. Kernel operations
b. mathematical computations (including memory addressing)
c. User interface and human factors (e.g. drawing graphics)
d. Error detection and correction (include software and hardware malfunction detection and recovery)
Again, maybe the answer will surprize you.
D. The uptime and fault tolerance of the phone system, in the US at least, is unrivaled.
Quote:
DW
P.S. happy coding, guys!
Yeah, and happy, umm, soldering there, Don. 8)
|