Re: LZ: Lots 'o questions...
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Re: LZ: Lots 'o questions...
On Sat, 27 Jul 1996, Joshua Lynch wrote:
> 2. I know the difference between ROM & RAM but what are the differences in
> accessing them?
They're at different addresses. I don't know the memory map of the
I suspect that anything from $0000 to $7FFF is ROM and anything from
$8000 to $FFFF is RAM. If I'm wrong maybe somebody else will jump
in and say so.
> 3. What portions of RAM can i use to store variables and such and are there
> specially
> allocated portions of RAM that i should not overwrite?
I don't know which are the safe areas yet but this is a good question
and there will be areas used by the 85 os that, if you overwrite them
will probably cause the 85 to crash when you do a rom call or when
your program terminates, or else make the 85 act weird in some way.
You can always use space allocated within your program as long as your
program doesnt have something important there. That's under your control.
There are probably other safe areas as well.
> 5. what are pages of memory? and what pupose do they serve?
Page is kind of a loose term referring to some division of memory.
What the division is depends on the system. 1024 bytes and 2048
bytes are common page sizes but there are lots of others in different
systems.
> 6. what is the difference between video memory and regular (if there such a
> thing) memory
Video memory is regular memory but it's used by the system to store the
stuff that goes on the screen. If the display is mapped into memory
then whatever is in that memory is always on the screen. There are
chips that read that area and write it to the screen every so often.
I don't know if the display is memory mapped in the 85. I do know it's
not in the TI-83. In the 83 video memory is just kind of a backup so
you can re-draw the screen if you have to, and it's optional. You can
use that memory for something else if you don't need it for that. In
a memory mapped display you can use the memory for something else but
it's gonna really make the screen look funny.
> I think thats all for now, I'll probably think of some more questions later.
> I think the first answer i'll get back is most likely a "TAKE A COMPUTER SCIENCE
> CLASS YOU BLUNDERING FOOL!!" but to tell you the truth i've nver taken a
> comp sci
> class in my life but im 19 and just starting college next month so please
> bear with my newbie/loser questions...
Take a computer science class if you want to help you get a job
but if you want to learn about computers you're doing it now.
Barry
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