CHR$(109) Variation

[[Category:Variorum]]
 10 PRINT CHR$(109+RND(1)*2);:GOTO 10

A striking difference between this version of the program and the more historical versions from 1982 and 1984 is the use of character codes 109 and 110, while the versions in the C64 ''User's Guide'' and ''Run'' magazine used character codes 205 and 206. The C64 guide notes that "CODES 192-223 SAME AS 96-127" (p. 137), so 109 and 110 are exactly the same as 205 and 206. 

The question arises, then, why might the early versions of the program have used the upper character values (205 and 206), especially when the PETSCII chart that appears in the C64 manual itself only lists the 109 and 110 values?

== Possible Explanations ==

Is it possible that the C64 designers simply wanted or needed to fill up the character code chart all the way up to the magic 8 byte number 255 (which is indeed the highest CHR$ code). Rather than inventing even more specialized graphic characters to go all the way to 255, they simply reused characters.

The reused characters begin at CHR$(192). As an appendix in the ''User's Guide'' explains:

<blockquote>192-223 are the same as 96-127</blockquote>
<blockquote>224-254 are the same as 160-190</blockquote>
<blockquote>255 is the same as 126</blockquote>