1st edition
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the 1st edition manual is dated nov 3, 1971
cc did not yet exist, but the unix v2 cc was made to work with the v1 kernel
there is a working unix v1 disk image created by combining the unix v1 kernel
with unix v2 userland programs

2nd edition
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the 2nd edition manual is dated june 12, 1972
cc existed in 2nd edition
there is no working unix v2 disk image

3rd edition
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the 3rd edition manual is dated feb 1973
cc existed in 3rd edition
there is no working unix v3 disk image

4th edition
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the 4th edition manual is dated nov 1973
cc existed in 4th editon
there is no working unix v4 disk image

5th edition
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the 5th edition manual is dated june 1974
getchar and putchar functions are available

6th edition
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the 6h edition manual is dated 1975
iolib 

7th edition
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the 7th edition manual is dated jan 1979