Re: REM <SHIFT+L>

From: Ethan Dicks (erd_at_infinet.com)
Date: 1998-09-21 16:50:05

> 
> Hello,
> 
> Can anyone tell me why the REM <SHIFT+L> trick works.  I'm sure you know
> what I'm talking about, but in case you don't...
> 
> On a C64, if you write a program like the following:
> 
> 10 PRINT"HELLO WORLD"
> 20 REM <SHIFT+L>
> 30 END
> 
> and then type LIST, you get:
> 
> 10 PRINT"HELLO WORLD"
> 20 REM
> ?SYNTAX ERROR
> 
> READY.
> 
> 
> The only investigation I've done is to look at the REM routine at 43323,
> but I saw nothing in the following opcodes that represents a shifted L.
> 
> Any help?

Back in the PET days, we used to poke odd tokens into REM statements to keep
our BASIC programs unlistable.  I think what you will find if you dump hex
for your line 20, is that the token following the REM token is out of bounds
and the lookup routine in LIST errors out when asked to translate that token
back into a printable word.  IIRC, we used to poke a 204 into a REM to screw
things up on a PET with BASIC 2.0 ROMs.  The table is larger for BASIC 4.0,
so it was a different value there.

-ethan

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