I'm drowning in PHP
londonperlmongers at iandocherty.com
Tue May 15 14:52:15 BST 2007
Jonathan McKeown wrote:
> Yes. On the Commodore PET the BASIC keywords were stored in a lookup table
> using this technique, and since shifted letters had the high bit set, you
> could abbreviate keywords by shifting:
> fO i=1 to 100 sT 5: ? i: nE
> (Didn't save anything but typing time: they were stored as one-byte tokens
> anyway AFAIR).
And in Spectrum BASIC numbers were stored redundantly as both binary (16
bit) and ASCII.
When the code was listed, it displayed the ASCII, when the program was
run it used the binary.
This gave a crude (but effective in those days) way of obfuscating the
program by changing the
ASCII but leaving the binary unchanged. It had the added benefic that if
anyone tried to edit
the code it became corrupted. :)
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