Big documentation update to go with hotplugging.

1 files changed, 14 insertions, 21 deletions

diff --git a/HACKING b/HACKING
index f8f8ca31..5a078e3a 100644
--- a/HACKING
+++ b/HACKING
@@ -20,31 +20,24 @@ space-separated fields:
 (1) The character length of the sentence containing the timestamp data
     (a GPRMC, GPLL, or GPGGA sentence)
 
-(2) A timestamp telling when gpsd received the data.
+(2) An offset from the D time telling when gpsd received the data.
 
-(3) An offset from the received timestamp telling when gpsd decoded the data.
+(3) An offset from the D time telling when gpsd decoded the data.
 
-(4) An offset from the received timestamp taken just before encoding the
+(4) An offset from the D time taken just before encoding the
     response -- effectively, when gpsd was polled to transmit the data.
 
-(5) An offset from the received timestamp telling when gpsd transmitted 
+(5) An offset from the D time telling when gpsd transmitted 
     the data.
 
-The spread between D and the Z timestamps measures components of the
-latency between the GPS's fix measurement and when it became available
-to the client. For it to be meaningful, the GPS has to ship timestamps
-with sub-second precision. SiRF-II and Evermore chipsets ship times
-with millisecond resolution.  Your machine's time reference must also
-be accurate to subsecond precision; I recommend using ntpd, which will
-normally give you about 15 microseconds precision (two orders of
-magnitude better than GPSes normally report).
-
-Another helpful command is B.  Without arguments, it triggers a response
-of the form <baudrate> <bits> N <stopbits>, e.g. "4800 8 N 1" describing
-the communications parameters of the link to the GPS.  If profiling is 
-enabled, B may be followed by an equals sign and a baud rate; the link
-will then change to that rate.  This feature is not enabled by default
-because it is not secured and can be used to effectively disable the GPS.
+The Z figures measure components of the latency between the GPS's fix
+measurement and when it became available to the client. For it to be
+meaningful, the GPS has to ship timestamps with sub-second
+precision. SiRF-II and Evermore chipsets ship times with millisecond
+resolution.  Your machine's time reference must also be accurate to
+subsecond precision; I recommend using ntpd, which will normally give
+you about 15 microseconds precision (two orders of magnitude better
+than GPSes report).
 
 The distribution lincludes a Python script, gpsprof, that uses the 
 Z command to collect profiling information from a running GPS instance.
@@ -105,7 +98,7 @@ Next, autoconfiguration...
 
 One of the design goals for gpsd is to be as near zero-configuration
 as possible.  Under most circumstances, it doesn't require either
-the GPS type or the serial-line parameters rto connect to it to be
+the GPS type or the serial-line parameters to connect to it to be
 specified.  Presently, here's how the autoconfig works.
 
 1. Ay each baud rate gpsd grabs packets until it sees either a
@@ -163,7 +156,7 @@ some funky initialization string.  Simply ship the string in the
 initializer for the NMEA driver.  Because vendor control strings live
 in vendor-specific namespaces (PSRF for SiRF, PGRM for Garmin, etc.)
 your initializing control string will almost certainly be ignored by
-anythinbg not specifically watching for it.
+anything not specifically watching for it.
 
 Another good thing to send from the NMEA initializer is probe strings.
 These are strings which shjould elicit an identifying response from