test-drb December 2006

test-drb@ccmp.vtda.org

225 participants
420 discussions

OT: South Pole was: Re: VCF 9 (Jay West) & (Jules Richardson)

by mtapley＠swri.edu

At 22:18 -0600 11/15/06, Sridhar wrote: >90 degrees south always points to the South Pole. It doesn't always >point to the same place, though. The precession of the Earth's >rotational axis causes the location of all coordinates on the Earth's >surface to shift by a small amount all the time. It's most easily >noticed at the poles. Barring smaller corrections of much shorter >period and magnitude, the Earth's axial precession occurs on a period of >about 26,000 years. All true, but partially unconnected and somewhat oversimplified. Earth's angular momentum vector precesses about the normal to the ecliptic (the plane of Earth's orbit) in a cone with half-angle 23.5 (or so) degrees and with a period of 26,000 years. This is directly driven by the lunar and solar tidal torque on the equatorial bulge of the Earth, which is in turn caused by the Earth's rotation. For a rigid body, this could happen without any change in the location of the "pole" as seen on the surface of the body. Independent of that (or of any external torque), the point at which the Earth's angular velocity (not momentum) vector intersects the surface, which is the instantaneous pole, wanders around on the surface. This is due to several things. One is the fact that the angular momentum and angular velocity may not be perfectly aligned. (Even a rigid body will do this if it is not spun along either its major or minor principle axis of inertia. This is the "polhode" motion of a freely rotating body as seen from the body.) Another is the fact that the Earth is continually rearranging its mass distribution by rainfall, earthquakes, ice-sheet melting, etc. etc., thus moving its principle axes of inertia around and causing the first condition to apply. (These mass redistributions are in turn driven primarily by the effects of incoming solar radiation, but this is an indirect effect of the sun on the system.) Another cause is due to the fact that the "solid" Earth is really a composite system, with many different solid and liquid components, many of which may be rotating with respect to one another and causing various interactions. I think I will stop there, acknowledging that I'm still oversimplifying. I will however add that I at one point in the early 1980's wrote a program in Fortran on a PDP-11 to display the current and predicted (by the IERS) Earth instantaneous pole coordinates on a Tektronix 4025 graphics terminal, erasing and re-drawing the predicted pole with every new update of the current pole. It was interesting to see how consistently off the predictions were. Sorry for the delayed-gratification nature of this post; I'm just getting back from 2 weeks' vacation. -- Mark Tapley, Dwarf Engineer (I haven't cleared my neighborhood) 210-379-4635 Dwarf Phone, 210-522-6025 Office Phone

17 years, 5 months

multiple cpu machines Re: rogues galleries

by chrism3667＠yahoo.com

someone set me strait if Im way off - is an emulator, like MAME in essence a parser essentially? I bet theres probably more to it then that though... --- cctalk-bounces at classiccmp.org <mbbrutman-cctalk at brutman.com> wrote: > > On the old standup arcade games multiple CPUs are common. > > Williams Defender uses two 6809 CPUs - one just for sound, and one for > everything else. > > Williams Joust is more complicated and uses four 6809s. > > > > Mike > ____________________________________________________________________________________ Do you Yahoo!? Everyone is raving about the all-new Yahoo! Mail beta. http://new.mail.yahoo.com

17 years, 5 months

Corporate genealogy?

by legalize＠xmission.com

Has anyone attempted to make a "big picture" view of the vendor landscape by creating a chart showing spin-offs and acquisitions of various vendors? I find this information sprinkled throughout Wikipedia, but no attempt at creating a "big picture" view. Has anyone done such a thing? -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

17 years, 5 months

multiple cpu machines Re: rogues galleries

by aliensrcooluk＠yahoo.co.uk

--- Jim Leonard <trixter at oldskool.org> wrote: > arcarlini at iee.org wrote: > >>> How about the Sega MegaDrive/Genesis? That ran a > 68000 and Z80. > > There have been many multi-cpu consoles; the Sega > Saturn had two Hitachi > RISC CPUs for core processing, plus a host of othe r > stuff for CDROM, > display, sound... The PlayStation 2 is also > dual-CPU. The PlayStation 3 > is a Cell monster, 7 cores you can play with, wrong!!! Some places state 9, but the last *official* CPU diagram I saw has 8 cores. One main core (slightly larger than the others) and 7 co-cores. (Does that make sense?) > although I think that's > been discussed here already by Mr. Brutman. > > My favorite was the Atari Jaguar, which had no les s > than: > > - a 32-bit RISC GPU > - a 64-bit RISC "object processor" > - a 64-bit RISC blitter > - a 64-bit general purpose DSP for audio and other > functions > - a 68000 for general-purpose helper functions > > And to shuffle memory around, a 64-bit DRAM > controller. > > The Atari Jaguar *should* have been the most > kick-ass console of its > generation (the blitter in particular was certainl y > the most powerful of > all the 5th-generation consoles). But it was so > complex that nobody > could figure out how to program it properly. > Coupled with legendary > Atari marketing fumbles, it died a quick death > before a suitable "killer > app" could be developed for it. > > Most coders unfamiliar with the system would treat > the Jaguar as a > 68000-based machine with a giant framebuffer, like > an Atari ST on > steroids. This was clearly not the best use of th e > machine. The Atari Jaguar is basically a Super Spectrum (SS). No I'm not kidding (surely someone here can back me up?). There is a page on the web somewhere explaining how the guys that were designing the SS ended up working for Atari. The SS evolved into the Atari Jaguar. Also, with the CD unit fitted into the Jaguar cartridge slot (so it could play Jaguar CD games - of which there must be about 6!) that add's yet another processor or two possibly. Regards, Andrew B aliensrcooluk at yahoo.co.uk

17 years, 5 months

Disk image conversions?

by rcini＠optonline.net

All: Here's an interesting one. I have several disk images for the Tandy 2000 that had been made with TeleDisk. One of the images is bad for some reason (must be truncated; won't get past track 30; complains that target disk drive is not ready when it reaches T30). The original disk is not available. I've done the basic troubleshooting on the drive and media (other images made with same new floppy diskette and drive work fine; swapped drive and media) to eliminate them from the failure tree. Even though TeleDisk seems to write to track 30 just fine, the disk is unusable. This is odd because it's an MS-DOS format (although 80T 9S) so all of the directory and media parameter info is at the front of the disk rather than the back. Is there anything I can do with this partial disk image to retrieve at least some of the info? Rich Rich Cini Collector of classic computers Lead engineer, Altair32 Emulator Web site: <http://highgate.comm.sfu.ca/~rcini/classiccmp/> http://highgate.comm.sfu.ca/~rcini/classiccmp/ Web site: http://www.altair32.com/ /***************************************************/

17 years, 5 months

Gentle Cleaners Used on Old Computers

by wizard＠voyager.net

Hey, all, I put together this list from the "Green Goo" thread. If anyone has more good information about various cleaners, or procurement information about ones listed, I would appreciate hearing about it, and I'll update the list. It could be handy -- maybe even a FAQ answer. Sincerely, Warren Wolfe ********************************************************** Gentle Cleaners Used on Old Computers. Caig DeOxIt - Remove oxidation from electronics, and clean - http://www.tubesandmore.com/ Caig ProGold - Seal and lube circuit card edge fingers, etc. - Radio Shack 64.4338 http://www.tubesandmore.com/ GooGone - Cleans off old adhesive residue. Mr. Clean - Cleans stains, discoloration, and magic marker from painted metal. Magic Eraser Afta - Cleans glues and residues - Home Depot CaiLube MCL - Cleans and lubes potentiometers, especially. - http://store.caig.com/s.nl/sc.2/category.183/.f

17 years, 5 months

OFFICIAL VCF EAST 4.0 date(s)

by evan＠snarc.net

This just in: we picked Saturday, June 9, and (probably) Sunday, June 10 as well. Hopefully we will determine the need for a second day soon. Someone, somewhere, will probably have a graduation-related conflict. To that person(s), I apologize, but we did our best. East 3.0 was awesome, but I gaurantee that East 4.0 will kick 3's ass!! - Evan

17 years, 5 months

Does this qualify as vintage computer?

by irisworld＠mac.com

Kind of neat: http://www.msnbc.msn.com/id/15984363/ Rob Robert Borsuk irisworld at mac.com -- (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination.

17 years, 5 months

Atom Toolkit. Was: rogues galleries

by fjkraan＠xs4all.nl

Gordon JC Pearce wrote: > No, but it does have an EPROM in the extension socket labelled "TOOLKIT > ROM #A000" or something similar. I've never quite figured that one out. > > Maybee this Atom toolkit: http://www.xs4all.nl/~fjkraan/comp/atom/toolkit.txt Fred Jan

17 years, 5 months

New Cipher 525 tape drive on ePay

by cclist＠sydex.com

Probably one of the first "floppy tapes". Item 320056306946. Cheers, Chuck

17 years, 5 months

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test-drb December 2006