Update documentation

sohstationviewer/documentation/05 _ Read Data.help.md

@@ -67,4 +67,15 @@ RT130 DASs will be listed for user to select for reading.
 Note: DASs list will be displayed in the File List box no matter the From Data
 Card checkbox is checked or not.
 <br />
-<br />
+
\ No newline at end of file
+# Limit time period to plot
+
+If only a specific time period in a data set needs to be plotted, the program can 
+limit plotting to only that time period. This is done by using the From and To Date 
+editors, located near the top right corner of the main window. In order to select 
+a date, click on the dropdown button. A calendar will be displayed, and the date 
+can be chosen. If the day of year is desired, check the Show DOY box and the day 
+of year will be displayed for each day in the calendar. 
+
+NOTE: the format the chosen date is shown in can be changed by changing the date 
+format in the Options menu (see the Options Menu section).

sohstationviewer/documentation/40 _ Firmware Notice.help.md

-Pegasus firmware was updated to record VEI in millivolts. 
-Previous versions of the firmware recorded VEI in microvolts.
+# Firmware notices
 
-We decided to apply VEI's conversion factor in newer version of Pegasus. 
-If user observe values higher than expected values for Pegasus, the data is of the older version.
+---------------------------
+---------------------------
\ No newline at end of file
+
+## Old Pegasus firmwares
+
+Some old Pegasus firmwares record a number of SOH channels in different units. 
+These channels included:
++ VEI: microvolts in old firmware, millivolts in new firmware
++ VDT: microdegrees C in old firmware, centidegrees C in new firmware
++ VM1-6: microvolts in old firmware, millivolts in new firmware
+
+Currently, SOHViewer only supports new versions of the Pegasus firmware. If the 
+plotted values of the channels listed above are higher than expected, the data 
+is recorded using old firmwares. If this happens, the affected channels can be 
+edited to reflect the old units (refer to the View-Edit Database Tables section).