STACK FRAMES

Stack frames for 16-bit interrupts are the same as for real mode.

The stack frame for 16-bit exceptions follows:

word SS

word SP - Original stack address

word Flags

word CS

word IP - Original Flags:CS:IP values that caused the exception

word Err Code - Processor supplied exception error code

word CS

word IP - Return address, returns to interrupt/exception

dispatch code

DEFAULT API

The default CauseWay API follows. Functions that end in the text near are intended only for backwards compatibility with CauseWay's NEAR memory model. This model is now obsolete. The assembly language program include file CW.INC also contains the following list.

AliasSel Create a read/write data selector from source selector.

Inputs: AX = 0ff06h

BX = Source selector

Outputs: Carry set on error else,

AX = New data selector

Errors: If an invalid selector is passed in BX, this function returns with carry set.

Notes: This function always creates a read/write data selector regardless of the source selector type. It can be used to provide write access to variables in a code segment.

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