[aprssig] APRSDOS and Soundcards
Stephen H. Smith
wa8lmf2 at aol.com
Mon Jan 15 21:26:25 EST 2007
bruninga at usna.edu wrote:
> Sorrry, APRSdos does not have hooks to a sound card. Simplest
> thing I can think of is to use a D7 HT with it's internal TNC.
> SO as, you say, all you have to buy is a "radio"... But it has
> to have the TNC built in.
>
> Bob
> WB4APR
>
>
>
No APRS or packet application has "hooks to a sound card". They only
need KISS or TCP/IP support. The soundcard softmodems appear to other
programs either as a KISS TNC device on a virtual serial port (MixW or
AGW Packet Engine), or as a TCP/IP network device (AGW Packet Engine).
The fundamental problems with using soundcard softmodems in DOS is:
1) RAM Cram. DOS basically can only use the first MB of RAM no
matter how many GBs of ram are in the machine. It's simply not enough
memory for the main application plus the soundcard hardware drivers plus
the soundcard modem application. [The driver alone for the typical
sound card today would more than fill the ENTIRE DOS memory space!]
2) DOS is not multitasking. Normally only one program at a time can
run in DOS, aside from some minor background pop-up RAM-resident
utilties. One would have to rewrite an application like AGW or MixW to
be a monster device driver, rather than a stand-alone program running
alongside DOSaprs. Recall the old DOS games. Each one had it's own
internal sound and video drivers. If your particular sound and video
hardware wasn't supported by a particular game, it would never work with
it.
--
Stephen H. Smith wa8lmf (at) aol.com
EchoLink Node: 14400 [Think bottom of the 2M band]
Home Page: http://wa8lmf.com --OR-- http://wa8lmf.net
NEW! TNC Test CD
http://wa8lmf.net/TNCtest
JavAPRS Filter Port 14580 Guide
http://wa8lmf.net/aprs/JAVaprsFilters.htm
"APRS 101" Explanation of APRS Path Selection & Digipeating
http://wa8lmf.net/DigiPaths
Updated "Rev G" APRS http://wa8lmf.net/aprs
Symbols Set for UI-View,
UIpoint and APRSplus:
More information about the aprssig
mailing list