Re: A86: System memory
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Re: A86: System memory
At 09:41 1998-02-25 +0100, you wrote:
>
>Can I use system memory area (start address at 0C000h) to store some
>programs data (graph buffers for example) ?
No.
>If not, what is stored in this area ?
Systemvariables. Check out ram86.inc
>What is its end address ?
$C000-$D747 contains system variables.
$D748-$FBFF is for assembly programs AND the stack.
$FC00-$FFFF video memory.
>There are floating point stack and operator stack on the RAM page 1.
>Where are stack pointers of them. If I'm not using floating point
>calculations in asm program, can I
>use all this RAM page to store my data ?
Yup! It seems so anyway. It's probably used whenever you call any
math routines, and used by the calc when calculating stuff. I wiped
the whole page out in a program, and I haven't seen any problems.
16k to play with :-)
You might accidently switch to another RAM page when dealing
with external variables. There are two rom calls to set the RAM page
to 1 and 7: (from ti86abs.inc)
_RAM_PAGE_1 equ 47E3h
_RAM_PAGE_7 equ 47F3h
All registers preserved.
--
Real name: Jimmy Mårdell
IRC......: Yarin
Email....: mailto:yarin@acc.umu.se <-- NEW E-MAIL ADDRESS!!!!
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