The BBC and Master Computer Public Domain Library

IWA = 8-bit or 16-bit Integer

Submitted by Steve Fewell

Routine: i16-bit
Name: IWA = 8-bit or 16-bit Integer
Starting Address: &AE1A for 16-bit value [or AE18 for 8-bit]
Entry criteria: A contains the least significant byte of the 16-bit number, Y contains the most significant byte of the 16-bit number.
[Y is always set to 0 when called from AE18, so only need to supply A].
Exit: IWA contains the 8-bit or 16-bit number [(256 * Y)  + A].

Description:
Stores an 8-bit [if called from AE18] or 16-bit [if called from AE1A] number (The 16-bit value is represented by 2 individual bytes) into the IWA and sets the 2 most significant bytes (or in the case or an 8-bit value, the 3 most significant bytes) of the IWA to zero.

Disassembly for the IWA = 8-bit or 16-bit Integer routine