ACROSS

1. m in F = ma
5. Roman counterpart of Greek Helios
8. Robin Williams' breakthrough role
12. Model or tennis player?
13. Cab payment
14. One born to Japanese immigrants
15. 1970s Crystal sitcom
16. She played Joanie on 18 across
17. Amorously looked upon
18. Richie Cunningham's TV show
20. Stepped or trampled
21. Commotion
22. Bleat
23. Roundabout way
26. John-Boy's TV family
30. Boat propeller
31. New York state liberal arts college
34. "____ empire"
35. Filth or dirt
37. Tolkien's Ogre-like creature
38. Deduce a principle
39. Carte du jour
40. Senseless or foolish behavior
42. Electronic display
43. Benign tumor of glandlike structure
45. Superior commands
47. A concession given to mollify
48. Bert's TV buddy
50. The Count's favorite subject
52. A Desilu production
56. Flycatcher bird
57. Swollen lymph node
58. Scat singer Fitzgerald
59. The pen is mightier than this?
60. Lazily
61. Afresh
62. Ailments
63. "Monkey ____, monkey do"
64. First light

DOWN

1. Ran longer than the war that served as its backdrop
2. Dwarf buffalo
3. Cinch
4. Greek lyric poet of Lesbos
5. Singer McLachlan
6. Official language of Indian state Orissa
7. Eye contact
8. Moved
9. Largest city of Norway
10. He helmed a TV "Bunch"
11. Cassidy's partner in crime
13. Indiana's hat
14. Pertaining to the dorsal
19. You have
22. "Cheers," e.g.
23. Proclaimed as true without proof
24. Dog-____ pages
25. Cardinal number, equals 1 + 1 + 1
26. Branch Davidians' showdown location
27. Immature ovum
28. Better than nice
29. Snowmobiles
32. Comes with a value meal?
33. _____ Lanka
36. Ghoulish sitcom family
38. Eagle's nest
40. One who's playfully mischievous
41. Line of trucks
44. "____ and aahed"
46. Remove lead
48. Escape
49. California oak
50. Whimper
51. Absent in military
52. Wading bird with down-curved bill
53. Bone in the human forearm
54. Ball of yarn
55. Tired sign
56. Pressure unit