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C----------------------------------------------------------------------
subroutine ftgbit(buffer,log8)
C decode the individual bits within the byte into an array of
C logical values. The corresponding logical value is set to
C true if the bit is set to 1.
C buffer i input integer containing the byte to be decoded
C log8 l output array of logical data values corresponding
C to the bits in the input buffer
C
C written by Wm Pence, HEASARC/GSFC, May 1992
integer buffer,tbuff
logical log8(8)
log8(1)=.false.
log8(2)=.false.
log8(3)=.false.
log8(4)=.false.
log8(5)=.false.
log8(6)=.false.
log8(7)=.false.
log8(8)=.false.
C test for special case: no bits are set
if (buffer .eq. 0)return
C This algorithm tests to see if each bit is set by testing
C the numerical value of the byte, starting with the most significant
C bit. If the bit is set, then it is reset to zero before testing
C the next most significant bit, and so on.
tbuff=buffer
C now decode the least significant byte
if (tbuff .gt. 127)then
log8(1)=.true.
tbuff=tbuff-128
end if
if (tbuff .gt. 63)then
log8(2)=.true.
tbuff=tbuff-64
end if
if (tbuff .gt. 31)then
log8(3)=.true.
tbuff=tbuff-32
end if
if (tbuff .gt. 15)then
log8(4)=.true.
tbuff=tbuff-16
end if
if (tbuff .gt. 7)then
log8(5)=.true.
tbuff=tbuff-8
end if
if (tbuff .gt. 3)then
log8(6)=.true.
tbuff=tbuff-4
end if
if (tbuff .gt. 1)then
log8(7)=.true.
tbuff=tbuff-2
end if
if (tbuff .eq. 1)then
log8(8)=.true.
end if
end
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