83Plus:OS:Memory Layout
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Revision as of 10:36, 9 December 2020 by NonstickAtom (Talk | contribs)
Memory Layout
This table describes how the RAM is organized.
| Address | Description |
|---|---|
| appData to userMem-1 | System RAM: Used by the OS to store various pointers, settings, buffers, etc. |
| userMem to (tempMem)-1 | User Memory: This is where all variables are stored. |
| (tempMem) to (FPBase)-1 | Temp Memory: This is where the OS stores temporary variables. |
| (FPBase) to (FPS)-1 | Floating Point Stack: A LIFO stack for floating point number (or variable names). |
| (FPS) to (OPS) | Free RAM. |
| (OPS)+1 to (OPBase) | Operator Stack: A LIFO stack used to parse expressions and to store return information when a TI-Basic program is called from another TI-Basic program. TI won't tell anything about this. |
| (OPBase)+1 to (pTemp) | Variable Allocation Table (VAT) for temporary variables. |
| (pTemp)+1 to (progPtr) | Variable Allocation Table (VAT) for programs,appvars,groups and lists with variable length names. |
| (progPtr)+1 to symTable | Variable Allocation Table (VAT) for all variables with a fixed name: reals, strings, ans, functions, matrices, etc. |
| symTable+1 to $FFFE | Hardware Stack |
the_mad_joob found that $FFFF is unused by the system. It is an extra scrap byte.
