RE: [amsat-bb] Looking for ... circuit design

[AG5RS Ron Sparks <rlssat1@xxxxxxxxxxxxx>]

Not long ago a ham friend gave me a couple of '386 half-ISA single board 
computers (SBC) from an obsolete industrial control.  I used them on 
projects similar to yours.  You can find '486 half-ISA SBCs all over so you 
might look around for some to scrounge.

Pros:  Small size, easy to use, no code to write (just use DOS), plenty of 
freeware available, can use pre-made external hardware like notebook 
drives, USB ports, etc.
Cons:  A bit pricey if you have to buy one (but if you add the cost of the 
PIC development system to the PIC they are not that much different), you 
don't have the fun of "roll-your-own".

Just my two cents worth.

Ron, AG5RS


At 06:50 PM 8/22/2004, Assi Friedman wrote:
>With fast computer processors and "stable" multi-threading it no longer
>makes sense to have a stand alone box do the orbit calculations. If I
>remember anything from the Trakbox days is how annoying it was when WISP and
>Trakbox disagreed. We are beyond those days of slow computers and any 4
>years old or newer computer can handle orbit propagation, station management
>and making coffee simultaneously. If you intend to do this with a PIC both
>code and data size will kill you because of the massive use of floating
>point variables and the math libraries. For a processor like a PIC, it makes
>much more sense to have the PC load an AZ/EL/UL-Freq/DL-Freq/Time table and
>have the PIC do interpolation. A PIC can handle an external serial EEPROM
>quite easily so I see no reason why you couldn't load a table to support 1
>second updates - even though that would be an overkill! PIC are great little
>gadgets for embedded control, they are awful if you try and turn them into a
>"real" computer. BTW, I believe Steve Bible N7HPR worked on a similar
>project a while ago, but I haven't checked the TAPR page to see if they
>currently kit it.
>Assi 4x1kx/kk7kx
>
>
>-----Original Message-----
>From: owner-AMSAT-BB@AMSAT.Org [mailto:owner-AMSAT-BB@AMSAT.Org]On
>
> >
> > I'm not so sure about that. InstantTrack can run an optimized PLAN-13
> > on a XT (8088 at 4.77 MHz without math co-processor) in well under a
> > second (and it flies in tens of milliseconds on an old SX!), and that
> > includes a screen update. The 18F452 claims up to 10 MIPS operation,
> > so it should be even faster than that. That would be fast enough, if
> > he can equal InstantTrack's level of code optimization.
>----
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