Classic Computer Magazine Archive COMPUTE! ISSUE 72 / MAY 1986 / PAGE 10

Readers Feedback

The Editors and Readers of COMPUTE!

Reading Apple Keys
I have just read Apple SpeedCalc in COMPUTE!'s February 1986 issue and noticed that the program's commands use the Open Apple and Closed Apple keys. How do you read those keys? They don't show up in INPUT statements or when the keyboard is read. Can I access them from BASIC or only from machine language?

David Reed

The Open Apple and Closed Apple keys, which appear only on Apple IIe and IIc computers, are easy to read from BASIC or machine language. Both can be read in BASIC by PEEKing certain memory locations. The value in location 49249 ($C061) is 128 or greater if the Open Apple key is pressed, and less than 128 if it is not. Location 49250 ($C062) gives the same information for the Closed Apple key. Here's a program fragment that gets a keypress and also checks these two special keys:

110 OA = PEEK(49249):CA =
120 IF K$ ="a" AND OA>= 128 AND
    CA<128 THEN GOSUB 1000

These statements call a subroutine at line 1000 if Open Apple-A is pressed, but not if Open Apple-Closed Apple-A is pressed.