The following features have been implemented:

feature set:
number entry
  0         yes
  1         yes
  2         yes
  3         yes
  4         yes
  5         yes
  6         yes
  7         yes
  8         yes
  9         yes
  .         yes
  equals    yes
  AC        yes
  C         yes
  +/-       yes
  A         no
  B         no
  C         no
  D         no
  E         no
  F         no
operations
  +         yes
  -         yes
  x         yes
  /         yes
  k         no
constants
  sh-1      yes
  sh-2      yes
  sh-3      yes
  sh-4      yes
  sh-5      yes
  sh-6      yes
  sh-7      yes
  sh-8      yes
  sh-9      yes
  sh-+      yes
  sh--      no
  sh-x      no
  sh-/      no
  exp-pi    yes
random number generator
  sh-.      yes
  sh-0      no
exps
  exp       yes
  eng       no
  !eng      no
  mode-7    no
  mode-8    no
  mode-9    no
percent
  sh-equals no
memory and registers
  X<->Y     no
  X<->M     no
  M+        no
  M-        no
  Min       no
  MR        no
computing
  NEG       no
  NOT       no
  AND       no
  OR        no
  XOR       no
  XNOR      no
bases
  mode-0    no
  mode-1    no
  mode-2    no
  mode-3    no
logarithms
  log       no
  ln        no
powers
  x^y       no
  x^1/y     no
  e^x       no
  10^x      no
  x^2       no
  sqrt      no
  cbrt      no
  1/x       no
  x!        no
fractions
  ' ' ''    no
  !' ' ''   no
  a b/c     no
  R<->P     no
  P<->R     no
calculus
  mode-4    no
  mode-5    no
  mode-6    no
  sin       no
  cos       no
  tan       no
  sh-sin    no
  sh-cos    no
  sh-tan    no
  sin-1     no
  sh-sin-1  no
  cos-1     no
  sh-cos-1  no
  tan-1     no
  sh-tan-1  no
conversions
  'F='C     no
  in=mm     no
  gal=l     no
  lb=kg     no
  oz=g      no
  cal=J     no
  mmHg=kPa  no
  atm=MPa   no
brackets
  [(...     no
  ...)]     no
stats
  sh-AC     no
  mode-.    no
  DEL       no
  !x        no
  sn        no
  sn-1      no
  xD        no
  Sx^2      no
  Sx        no
  n         no