Re: Pointer at the start of a BASIC line: what good is it?

From: Rhialto <rhialto_at_falu.nl>
Date: Sat, 30 Oct 2021 22:55:14 +0200
Message-ID: <YX2xMhIWgtLZPlFD_at_falu.nl>
On Sat 30 Oct 2021 at 20:51:14 +0200, silverdr_at_srebrnysen.com wrote:
> Hi Ruud!
> 
> > On 2021-10-30, at 09:20, ruud_at_baltissen.org <ruud@Baltissen.org> wrote:
> > 
> > [?]
> > But then I fired my C128 up and.... the bloody computer does handle 
> > longer lines well and there goes my "80 characters only" scheme. So 
> > it seems that, if I want to keep this compatibility claim, I have to 
> > use a table or whatever solution as well. 
> 
> But? the lines table is (nomen omen) basically needed for the screen
> editor, which had to adapt to 40 columns and differentiate between
> "logical" and "physical" lines, isn't it? BASIC AFAIR doesn't care, as
> long as the program/lines structure remains correct. Please someone
> correct me if I am wrong here. It's been some time since I used to
> POKE oversized BASIC lines into my 64 ;-)

The limitation is on the length of the input that you can type, not on
how long this will be when tokenized.

The text on the screen is first copied into the input buffer, and then
tokenized. In practice the tokenized version is almost always shorter;
it can't be longer.  The basic input buffer ($0200-$0258) is more than
80 bytes long (89) but that's only because the VIC-20 could link 4
screen lines together, making 88 characters.  Since the 64 links only 2
lines (80 characters), the extra space won't help you in practice.

But with poke trickery or somesuch you can make longer basic lines.
There is probably a limit of 255 bytes somewhere though.

-Olaf.
-- 
___ "Buying carbon credits is a bit like a serial killer paying someone else to
\X/  have kids to make his activity cost neutral." -The BOFH    falu.nl_at_rhialto



Received on 2021-10-30 23:00:05

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