On January 18, 2026 12:05:35 PM PST, "John R. Hogerhuis" <[email protected]>
wrote:
>
>BTW, you could use Peek/poke and math.
Perfect!
>You might also try using VARPTR to make a special string that points at the
>LCD, then you can use string operations to mess with it.
Interesting idea. Of course it isn't necessary now that you've pointed me to
where the screen is mapped in memory, but I'm curious about the suggestion as I
don't know how to do it.
First. I don't quite understand string space allocation. I can't have a string
of length 640, right? I tried DIM R$(16) thinking maybe if I set each of the 16
rows to SPACE$(40), it would pack it reasonably efficiently in RAM. But, no, I
had to reserve extra memory using CLEAR before it would let me even use DIM. It
ended up using significantly more memory than the other methods. Is the idea
that the "wasted" space would be used by other strings in the program?
What sort of string operations were you thinking of? Does Model-T BASIC allow
one to put MID$() on the left-hand side of an assignment? If so, is it swift?
My recollection was that string operations were notoriously slow in BASIC, but
maybe that's just because in the past I have been unknowingly incurring memory
allocations and copies.
Are there certain string tricks which are fast enough for animation? For
example, can one make a horizontal scroller by shifting the string pointer?
--b9
