Commodore PET User Manual page 339

Character Representation
ASCII (American Standard Code for Information Interchange) is a
widely used code for representing character data. It is nominally a 7-bit
code, allowing 128 characters (7F16=1281 0) ta be represented. The stan-
dard ASCII 7-bit character set is shawn in Table 6-4. Bits are numbered fram 0
(Ieast significant bit) to 6 (most significant bit):
7 6 5 4 3 2 1 0
~
Bit number
II[IJ
AS?II cpde
rn
(7-bit ASCII)
The first 32 codes are reserved for non-printable control characters. intended for
message formatting and print format control.
On the PET, characters are stored in ASCII format but in anextended
version using eight bits. With eight bits normally available, rather than just
seven, up ta 255 characters can be represented. Within compressed BASIC
text the 8-bit character codes are interpreted as shawn in Table 6-3, where
the eighth bit on signifies a keyword. Eisewhere in main memory the 8-bit
character codes are interpreted as shawn in Appendix A.
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