83Plus:BCALLs:45CD

This article is missing some information (namely Destroys). You can help WikiTI by filling in the missing information.

Synopsis

Official Name: PullDownChk

BCALL Address: 45CD

Checks for and processes any keys relating to menus.

Inputs

• A = key press

Outputs

• A = key press (might not be the same)

Registers Destroyed

• unknown

Comments

Calling this immediately after GetKey will allow OS menus to appear during execution of your program. The output of this routine may be an unprocessed key or it may be the result of a menu action. For instance if a=kenter was sent to this routine while entry 2 is highlighted in the Draw menu, the output of this routine would be a=kLine.

Example

ld a,kDraw
B_CALL PullDownChk ;on LCD the draw menu should be visable
ld a,kDown
B_CALL PullDownChk ;cursor should move from entry 1 to entry 2
ld a,kEnter
B_CALL PullDownChk ;output of routine should be kLine