83Plus:BCALLs:4045

Synopsis

Official Name: callMain

BCALL Address: 4045

Calls the cxMain vector.

Inputs

Typically the OS expects the following inputs:

• a = key to send to cxMain
• (keyExtend) = second byte of key press, if it exists

Outputs

• This varies depending on the routine in use.

Registers Destroyed

• HL is preserved. All other registers depend on the current CxMain routine in use.

Comments

This BCALL calls the routine on page (CxPage), at address (CxMain). When starting an app normally, the default is usually a dummy return. The OS sends key presses to this routine for proper handling.