Introduction

TI-83+/TI-84+ assembly API

BBC BASIC (Z80) for the TI-83+/TI-84+ provides two standard ways to access its extensive library:

BASIC keywords such as PRINT or GET.
BBC Micro MOS API routines such as OSWORD or OSGBPB.

A third way has been added to the TI-83+ and TI-84+ version of BBC BASIC (Z80). This will unfortunately result in programs that do not run in other versions of BBC BASIC but does provide access to some useful routines.

Invoking the routines

Each routine is assigned a number which is loaded into the accumulator (A%). The BASIC CALL statement is then used to call &4083, the entrypoint for the assembly API, along with any arguments. For example, routine 1, UCASE$, could be invoked like this:

str$="Hello"
A%=1:CALL&4083,str$

The routines are designed to be easy to invoke from BASIC. If you need to invoke them from assembly then you will need to pass the address of a parameter table in RAM in IX - see CALL for more information.

Unless otherwise stated all regular registers are destroyed.