[plug] Interference

[Buddrige, David]

I don't know if one exists or not, but usually I find you can noramally
find out, by going to either a search engine like www.hotbot.com or
alternately http://x13.dejanews.com/home_ps.shtml and searching for
keywords like "linux HP48G emulator"... it's rare I find to not find
*something*...  hang on... *just doing web-search*............

got this from a site: http://www.engr.uvic.ca/~aschoorl/faq/48faq-2.html

2.11 Are there any HP48 Emulators? 

A fully functional HP48 emulator by Eddie Dost called "x48" is
available. It runs in X-Windows on any Unix based
operating system like Linux or Solaris. However, it requires a ROM dump
of an HP48 to run. Of course, due to
copyright laws such a ROM dump cannot be distributed with the x48
package. 

Therefore, you must be the proud owner of an HP48 (S/SX or G/GX) in
order to create your own ROM dump. The
emulator will look and act either like a S/SX or a G/GX, depending on
what type of ROM dump you give it. Further
instructions are contained in the x48 package itself. The latest version
of x48 is available at
ftp://ftp.cis.com/pub/hp48g/uploads/x48-040.zip

There is also a freeware emulator for Windows called Emu48. It is
written by Sebastien Carlier, and runs under either
Windows 95 or NT. It offers many exciting features, including fast
speed, saving of memory, direct loading of files onto
the stack, a greatly customizable interface, and support for ports
through 33. It supports both S/SX and G/GX ROM
dumps, and comes with a "RomDump Wizard" to help you create one. 

The binaries and full C++ source code, distributed under the GNU Public
License, as well as more information, are
available at http://www.geocities.com/CapeCanaveral/5948/

An emulator for the HP38, based on Emu48 has also been created. It is
available at
http://www.epita.fr/~avenar_j/hp/38.html

There is also an HP48 S/SX/G/GX Emulator for Amiga computers called
Alcuin. See
http://www.cis.tu-graz.ac.at/home/schupfer/Alcuin/index.html for more
information. 

regards

David Buddrige
Software Engineer
MITS Ltd.
david.buddrige at mitswa.com.au

> -----Original Message-----
> From:	Tony Clark [SMTP:tony at ballist.net.au]
> Sent:	Wednesday, November 25, 1998 4:22 PM
> To:	plug at linux.org.au
> Subject:	Re: [plug] Interference
> 
> While this has little to do with linux, personally I find it an
> interesting
> subject.  To keep it on topic, has anyone got an HP48G emulator to run
> on
> linux  :)
> 
> >
> >	This may or may not work. Assuming that you are trying to
> >achieve 56k, this 
> >	would require a signal of 56+ kHz while your friendly local
> >transmitter will be 
> >	pumping out 700-740 kHz (720[6WF]+/-20kHz). Some calcs will be
> >required to get 
> >	the parameters just right. Any filtering WILL degrade the signal
> >performance.
> 
> This not actually correct.  The upper limit of a standard PSTN line in
> terms of frequency is 3.4KHz.  The exhange won't pass anything higher
> than
> that.  This is why filtering should and if done correctly will work.
> You
> should be able to get around 24dB of attenuation at the interfering
> frequency using a simple second order filter.
> 
> >
> >I think that you'll find that the underlying signalling rate for a
> >56kb/s is 9600 baud
> 
> The underlying symbol rate can't and won't be any higher than 3400 or
> 3400
> baud.  You will need a damm good line for that also.  The main reason
> that
> there are few if any reliable connections actually at 56K.
> 
> >
> >Encyclopaedia Britannica says...
> >
> >"In addition to the elementary forms of digital modulation described
> >above, there exist more advanced methods that result from a
> >superposition of multiple modulating signals. An example of the
> latter
> >form of modulation is quadrature amplitude modulation (QAM). QAM
> signals
> 
> 56K doesn't use digital modulation priciples.  Nyquist would and does
> come
> into play if you go down that root hence the 33k limit on V34 which is
> digital modulation.
> 
> 56K uses the decrete level to represent a symbol.  I need would need
> to
> read up a little but of the 256 possible levels about 160 are used.
> 
> Now back to HP48G emulator and linux :)
> 
> 
> Tony Clark
> 
> Digital and System Groups Manager
> ERG Telecommunications
> 
> Mobile Asia +852 93168907
> Australia   +61 411577715