``````* Cryptanalysis Problem (CLASSIFIED) (pipelined)
``````a GREG
``````b GREG
``````bb GREG
``````c GREG
``````t GREG
``````x GREG
``````y GREG
``````       LOC Data_Segment
``````freq   GREG @           Base address for byte counts
``````       LOC @+8*(1<<8)   Space for the byte frequencies
``````p      GREG @
``````       BYTE "abracadabraa",0,"abc" Trivial test data
``````ones   GREG #0101010101010101
``````       LOC  #100
``````Start  LDOU a,p,0
``````       INCL p,8
``````       BDIF t,ones,a
``````       BNZ  t,3F        Do main loop, unless near the end.
``````2H     SRU  b,a,53
``````       LDO  c,freq,b   Load old count.
``````       SLU  bb,a,8
``````       INCL c,1
``````       SRU  bb,bb,53
``````       STO  c,freq,b   Store new count.
``````       LDO  c,freq,bb
``````       SLU  b,a,16
``````       INCL c,1
``````       SRU  b,b,53
``````       STO  c,freq,bb
``````       LDO  c,freq,b   Load old count.
``````       SLU  bb,a,24
``````       INCL c,1
``````       SRU  bb,bb,53
``````       STO  c,freq,b   Store new count.
``````       LDO  c,freq,bb
``````       SLU  b,a,32
``````       INCL c,1
``````       SRU  b,b,53
``````       STO  c,freq,bb
``````       LDO  c,freq,b   Load old count.
``````       SLU  bb,a,40
``````       INCL c,1
``````       SRU  bb,bb,53
``````       STO  c,freq,b   Store new count.
``````       LDO  c,freq,bb
``````       SLU  b,a,48
``````       INCL c,1
``````       SRU  b,b,53
``````       STO  c,freq,bb
``````       LDO  c,freq,b   Load old count.
``````       SLU  bb,a,56
``````       INCL c,1
``````       SRU  bb,bb,53
``````       STO  c,freq,b   Store new count.
``````       LDO  c,freq,bb
``````       LDOU a,p,0
``````       INCL p,8
``````       INCL c,1
``````       BDIF t,ones,a
``````       STO  c,freq,bb
``````       PBZ  t,2B        Do main loop, unless near the end.
``````3H     SRU  b,a,53
``````       LDO  c,freq,b   Load old count.
``````       INCL c,1
``````       STO  c,freq,b   Store new count.
``````       SRU  b,b,3
``````       SLU  a,a,8
``````       PBNZ b,3B        Continue unless done.
``````       POP
``````
``````Main   IS   Start
``````
``````