Anyone can explain this code please? (Read temperature with DS1620 +pic 16F628)

[crynof]

I have this code (DS1620 with PIC 16F628), and was trying to understand how works, but i dont know whats means the variables.

Anyone can explain me this code??

include "Modedefs.bas
DEFINE OSC = 4
VRCON = 0
TRISA= %00000000
TRISB = % 00000000
CFGW CON $0C
CPUCN CON $02
START CON $EE
GETT CON $AA
STH CON $01
STL CON $02

DST var PortB.0
CLK Var PortB.1
RST var PortB.2
SER var PortB.3
Temp var byte
GCel var byte

gosub Init
GoSUB SetHL
gosub LetGo

e_go:
gosub Lee_T
GCel = Temp /2
serout ser,N2400,[GCel]
pause 250
goto e_go
end

Init:
High RST
shiftout DST,CLK,LSBFIRST,[CFGW,CPUCN]
low RST
pause 10
return

LetGo
high RST
shiftout DST,CLK,LSBFIRST,[START]
low RST
pause 10
return

Lee_T:
high RST
shiftout DST,CLK,LSBFIRST,[GetT]
shiftin DST,CLK,LSBPRE,[Temp]
low RST
return

SetHL:
high RST
shiftout DST,CLK,LSBFIRST,[SHL,48\9]
low RST
pause 10
high RST
shiftout DST,CLK,LSBFIRST,[STL,34\9]
low RST
pause 10
return

Thanks!!