Apple II Technical Notes Developer Technical Support
Revised by: Matt Deatherage November 1990
Revised by: Rilla Reynolds November 1985
This Technical Note formerly described a protocol which allowed applications to check a device which matched the mouse firmware identification for support of interrupts. Changes since November 1988: Added the mouse ID bytes since they are no longer included in other documentation.
The convention formerly described by this Note has been removed since it conflicted with the Pascal 1.1 Firmware Protocol. The conflict could cause Pascal to believe that optional firmware routines were present, when the card being checked was simply stating that it supported interrupts.
Apple recommends that any mouse-type device which matches the mouse ID bytes should support interrupts exactly as the Apple mouse firmware does. Applications which believe they have found an Apple mouse have a reasonable right to expect that the device they actually have found behave as an Apple mouse.
In addition to the standard Pascal 1.1 Firmware Protocol ID bytes, the AppleMouse II card is identified by a value of $20 at $Cn0C ("X-Y Pointing device, type zero") and a value of $D6 at $CnFB, where n is the slot number. The $CnFB value is not part of the Pascal 1.1 Firmware Protocol.