View source for 83:ROMCalls:4062

[[Category:83:ROMCalls:By Name:Other|Initialize]] [[Category:83:ROMCalls:By Name|Initialize]] [[Category:83:ROMCalls:By Address|4062 - Initialize]]
== Synopsis ==
'''Official Name:''' Initialize

'''Call Address:''' 4062

This routine resets all RAM and jumps to [[83:ROMCalls:401B|Mon]].

=== Inputs ===
''None''

=== Outputs ===
This routine does not return.

== Details ==
* out ([[83:Ports:00|00]]),C0
* ld sp,FFFF
* load zero into 8000-FFFF,0000
* initialize RAM with default values
* setup default error handler ([[83:ROMCalls:4056|MonErrHand]])
* save SP at [[83:RAM:817D|onSP]]
* display "Mem cleared"
* call [[83:ROMCalls:4775|HomeUp]]
* call [[83:ROMCalls:4805|CursorOn]]
* clear [[83:RAM:8000|kbdScanCode]] by calling [[83:ROMCalls:4014|GetCSC]]
* call [[83:ROMCalls:4CFE|GetKey]] (read: wait for a key)
** Before this call, bit onClrScrn,(iy+[[83:Flags:09|onFlags]]) has been set so when the user turns off the calculator, the on-key interrupt handler will clear the screen when the calculator is turned on again. This is necessary because when you press the on-key to turn the calculator on, the on-key interrupt handler does not return, but resets SP using [[83:RAM:817D|onSP]] and jumps directly to [[83:ROMCalls:401B|Mon]].
* call [[83:ROMCalls:4761|ClrScrn]] to remove the "Mem cleared" message on the first keypress.
* res onClrScrn,(iy+[[83:Flags:09|onFlags]])
* jump to [[83:ROMCalls:401E|MonForceKey]] to handle the keypress returned by the [[83:ROMCalls:4CFE|GetKey]] call and hand over control to [[83:ROMCalls:401B|Mon]].