document how it works, and bug, and ignore file "t"

diff --git a/hostside/.cvsignore b/hostside/.cvsignore
index f34b99157332a8c6513767fab7e729a4af9f8f04..e8f16d8d905c5712d341333dcda7c3ffe8022298 100644 (file)
--- a/hostside/.cvsignore
+++ b/hostside/.cvsignore
@@ -1 +1,2 @@
 hostside
+t

diff --git a/hostside/README b/hostside/README
new file mode 100644 (file)
index 0000000..c18d98d
--- /dev/null
+++ b/hostside/README
@@ -0,0 +1,21 @@
+./hostside /dev/ttyS0 <hex-digit-pairs> c|r|n
+
+ c = send directly to serial port as specified
+ r = nmra packet with checksum - encode for pic (including preamble) and send
+ n = nmra packet without checksum
+
+Eg,
+ ./hostside /dev/ttyS0 0348 n
+to tell decoder 3 to go speed 13 forwards
+
+ 7f       7f       00       64       41       97         output bytes
+ 01111111 01111111 00000000 01101000 01000001 10010111   as bits
+ >1111111 >1111111 >0000000 >1101000 >1000001 $0010111   top bit: >/$ for pic
+ 
+ 1111111 1111111  0 00000011 0 10001000 0 01001011 1     reorg bits for nmra:
+  preamble (14)   S 0AAAAAAA P 
+
+        MISTAKE it should be P 01DCSSSS
+
+To test:
+ >t; ./hostside t 0348 n && binview t